Page summary

https://www.proantic.com/galerie/guillaumerullier/

Tested 2026-09-23 01:34:53 using Chrome 151.0.7922.75 (runtime settings)

SummaryWaterfallMetricsRenderingCoachPageXrayCPUThird partyaxe

This page is fast to paint, snappy to interact with, visually stable and follows best practices, but missing some accessibility basics and weak on user privacy.

73 / 100
Coach overall
76 / 100
Performance
91 / 100
Best practice
62 / 100
Privacy

How it loaded →

0 → 1.479 s · median run
Frame at 0 ms
start
Frame at 600 ms
600 ms
Frame at 800 ms
Largest paint800 ms
Frame at 1100 ms
1.100 s
Frame at 1300 ms
1.300 s
Frame at 1500 ms
Complete1.500 s
600 ms
First Visual Change
881 ms
Speed Index
1.311 s
Visual Complete 85%
1.479 s
Last Visual Change
TTFB104 msLCP656 msTBT168 msCLS0.02
0
Critical violations
2
Serious violations
2
Moderate violations
0
Minor violations

What to act on · top recommendations

Add decoding="async" to non-critical images

0 / 100

The page has 72 images (out of 72) without a decoding hint. Add decoding="async" to non-critical images so the browser can decode them off the main thread.

Avoid using Google Tag Manager.

0 / 100

The page is using Google Tag Manager, this is a performance risk since non-tech users can add JavaScript to your page.

Avoid CPU Long Tasks

0 / 100

The page has 5 CPU long tasks with the total of 492 ms. The total blocking time is 168 ms and 1 long task before first contentful paint with total time of 124 ms. However the CPU Long Task is depending on the computer/phones actual CPU speed, so you should measure this on the same type of the device that your user is using. Use Geckoprofiler for Firefox or Chromes tracelog to debug your long tasks.

Fix accessibility violations

axe-core

axe-core flagged 2 high-impact accessibility violations (0 critical, 2 serious). Open the Accessibility tab to see the offending elements.

Google Web Vitals

min · median · mean · max of 3 runs
MetricMinMedianMeanMaxRuns agree?
Time To First Byte (TTFB)96 ms104 ms105 ms116 msvaries ±10%
Largest Contentful Paint (LCP)632 ms656 ms669 ms720 msvaries ±7%
Cumulative Layout Shift (CLS)0.00940.01550.01350.0155runs disagree ±20%

Visual Metrics

min · median · mean · max of 3 runs
MetricMinMedianMeanMaxRuns agree?
First visual change500 ms600 ms568 ms605 msvaries ±9%
Last visual change1.366 s1.479 s1.526 s1.733 sruns disagree ±12%
Speed index773 ms881 ms851 ms900 msvaries ±7%
Largest image1.200 s1.311 s1.304 s1.400 svaries ±8%
Heading633 ms733 ms702 ms740 msvaries ±7%
Largest contentful paint1.200 s1.311 s1.304 s1.400 svaries ±8%
Last meaningful paint1.200 s1.311 s1.304 s1.400 svaries ±8%
Visual readiness866 ms874 ms958 ms1.133 sruns disagree ±15%
Visual complete 851.200 s1.311 s1.315 s1.433 svaries ±9%
Visual complete 951.333 s1.479 s1.515 s1.733 sruns disagree ±14%
Visual complete 991.366 s1.479 s1.526 s1.733 sruns disagree ±12%

CPU

min · median · mean · max of 3 runs
MetricMinMedianMeanMaxRuns agree?
Total Blocking Time167 ms168 ms172 ms182 msstable ±4%
Max Potential FID118 ms121 ms124 ms133 msvaries ±6%
CPU long tasks 5556varies ±10%
CPU last long task happens at1.877 s2.219 s2.514 s3.446 sruns disagree ±35%

More metrics

min · median · mean · max of 3 runs
MetricMinMedianMeanMaxRuns agree?
First paint480 ms580 ms556 ms608 msruns disagree ±11%
Load event end1.628 s1.966 s2.155 s2.871 sruns disagree ±32%

Waterfall

Run 1 SpeedIndex median

First paintFCPLCPDOMContentLoadedDOM interactiveLoadRender-blockingRedirectError

Rendering

Run 1 · median
0.000 s
0s0.5s1s1.5s

The red band on the timeline marks when the main thread was busy with long tasks: moments when the page could not paint or respond, however the video looks.

Download video

Filmstrip

12 frames

Use --filmstrip.showAll to show all filmstrips.

Frame at 0 ms
0 ms
0 %
Frame at 500 ms
500 ms
0 %
Frame at 600 ms
600 ms
0 %
Frame at 700 ms
700 ms
45 %
Frame at 800 ms
800 ms
57 %
Frame at 900 ms
900 ms
60 %
Frame at 1.000 s
1.000 s
65 %
Frame at 1.100 s
1.100 s
71 %
Frame at 1.200 s
1.200 s
77 %
Frame at 1.300 s
1.300 s
83 %
Frame at 1.400 s
1.400 s
89 %
Frame at 1.500 s
1.500 s
100 %

Click a frame to seek the video to that moment. The dot marks frames where the page changed visually.

Frames

How smoothly Chrome delivered frames to the screen during the test. Dropped counts only frames Chrome flags as affecting smoothness. On mostly-static pages the longest gap includes idle time where there was simply nothing to draw.

Frames shown97
Partial1
Dropped0
Effective FPS58
Longest gap79 msat 577 ms

Why was rendering delayed?

Rendering was not meaningfully delayed. First paint landed at 580 ms on a 116 ms first byte; the 6 render-blocking requests were done by 411 ms and the remaining ~169 ms is style and layout work (47 ms of it measured style recalculation). The largest paint followed at 720 ms.

Style recalculation

measured by Chrome during this run

Style the browser had to recalculate before it could paint: many elements or a lot of time spent here points at expensive CSS on the critical rendering path. The recalculation count and the largest single one tell the two problems apart: one massive style change touching most of the page (few recalculations, the largest close to the total) needs different medicine than thousands of tiny ones (many recalculations, each tiny).

One large recalculation dominates. Restyling 1 264 elements cost 47 ms before the page painted (8 % of the time to First Contentful Paint), and a single recalculation of 1 253 elements accounts for 46 ms of it. Look for one class or inline-style change on a large container near the top of the DOM that restyles the whole subtree at once. The changes driving it are listed under Style invalidations below.

Before first contentful paint

Recalculations3
Elements1264
Total time46.649 ms
Largest recalculation1253 elements · 46.087 ms

Before largest contentful paint

Recalculations10
Elements1276
Total time57.073 ms
Largest recalculation1253 elements · 46.087 ms

The recalculation work before first paint is 8 % of the time to First Contentful Paint.

Forced reflows before the page painted

measured by Chrome during this run

JavaScript read a layout value (offsetTop, getBoundingClientRect, …) while the page was mid-change, so the browser had to re-layout synchronously, work that blocks rendering. Reflows before First Contentful Paint delayed the first pixels; reflows before Largest Contentful Paint delayed the main content.

Forced reflows before FCP0
Time spent in forced reflows before FCP0 ms
Forced reflows before LCP4
Time spent in forced reflows before LCP15 ms

That is 2.1 % of the time to Largest Contentful Paint. The number of reflows matters more than the milliseconds: layout thrashing multiplies on slower devices.

See every forced reflow for the whole page load on the CPU tab

Render blocking requests

13 requests · 671.0 KB

Blocking requests delay both paints: the browser renders nothing until they arrive, so they push First Contentful Paint and everything after it, including the largest paint (LCP). Requests that block the parser inside the body stall everything after them in the document. Load JavaScript with defer or async, and keep non-critical CSS off the critical path with media attributes. Bars show when each request loaded on a clock that runs to the last paint (the dashed line is FCP, the clock ends at LCP); the gap after the bars is style and layout work. Web fonts are context, not blockers: text renders invisible or in a fallback face while they load, so a font finishing after a paint is the classic reason text changed late.

RequestWhen it loadedTransferDownload
document
www.proantic.com · TTFB 116 ms
117 ms
38.0 KB116 ms
javascript · www.gstatic.com
1.280 s · past LCP
346.8 KB1.280 s
css · www.proantic.com
276 ms
40.5 KB276 ms
css · www.proantic.com
59 ms
19.0 KB59 ms
css · www.proantic.com
50 ms
8.9 KB50 ms
css · www.proantic.com
48 ms
879 B48 ms
css · www.proantic.com
47 ms
662 B47 ms
css · www.proantic.com
31 ms
1.9 KB31 ms
css · www.gstatic.com
loaded after LCP, at 1.638 s
41.4 KB8 ms
5 more requests
all done by 1.121 s
211.1 KB
LCP resource
indexImage.jpg — downloaded by 205 ms, rendered at 720 ms
61 ms
43.6 KB61 ms
web font · www.proantic.com · finished after first paint
568 ms · past LCP
378.5 KB568 ms
web font · www.proantic.com · finished after first paint
863 ms · past LCP
265.4 KB863 ms
web font · fonts.gstatic.com · finished after first paint
loaded after LCP, at 1.843 s
39.2 KB114 ms
0180 ms360 msFCP 580 msLCP 720 ms

Style invalidations

Why the browser had to recalculate style and layout: every DOM/style change invalidates some set of nodes, and the same class or attribute churning over and over is the pattern to hunt. Counts, not milliseconds: the time is in the style recalculation numbers above.

Chase what keeps changing after the page is up. 78 style recalculations and 2 211 layout invalidations fired after first paint, on a page the user was already looking at. The biggest driver is pseudo disabled (4×). Start with the script under "Scripts causing invalidations" that keeps triggering it.

Style recalculations10578 after first paint
Layout invalidations3 9232 211 after first paint

Changes that keep invalidating

top 4
  • pseudo: disabled4×
  • pseudo: enabled4×
  • attribute: disabled1×
  • attribute: class1×

Invalidation reasons

split at first paint

Between first and largest paint

Invalidations while the largest paint was still pending, so these delayed it.

ReasonStyle recalculationsLayout
A node was inserted into the page16–
An animation updated stylesAnimate transform and opacity so the compositor can run it off the main thread.1–
Related style rule5–
JavaScript changed an inline styleSet a class instead of writing element.style, so the browser can batch the work.4–
A web font finished loadingPreload the font or use font-display so a late swap does not re-style the page.–1 999
An element entered layout–2
An element's size changed–20
An element left layout–8

After the largest paint

Churn on the fully rendered page: wasted work and possible jank, but no paint delay.

ReasonStyle recalculationsLayout
A node was inserted into the page23–
An animation updated stylesAnimate transform and opacity so the compositor can run it off the main thread.23–
Frame6–
A web font finished loadingPreload the font or use font-display so a late swap does not re-style the page.–123
An element entered layout–54
An element left layout–2
Scrollbar changed–2
A style change forced layout–1

Before first paint: building the page

The page being constructed and styled for the first render. Expected work, shown for scale.

ReasonStyle recalculationsLayout
A node was inserted into the page26–
A stylesheet rule changed1–
An element entered layout–1 709
An element left layout–3

Scripts causing invalidations

top 3

Coach

The coach helps you find performance problems on your web page using web performance best practice rules. And gives you advice on privacy and best practices. Tested using Coach-core version 9.2.1.

Performance advice

76
12 warnings4 info
infoAdd decoding="async" to non-critical imagesdecodingAsync

The page has 72 images (out of 72) without a decoding hint. Add decoding="async" to non-critical images so the browser can decode them off the main thread.

Setting decoding="async" on an <img> tells the browser it can decode the image off the main thread, which keeps the page responsive to user interactions while images are being processed. The default ("auto") leaves the choice to the browser. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#decoding

Offenders
warn(0)Avoid using Google Tag Manager.googleTagManager

The page is using Google Tag Manager, this is a performance risk since non-tech users can add JavaScript to your page.

Google Tag Manager makes it possible for non tech users to add scripts to your page that will downgrade performance.

warn(0)Avoid CPU Long TaskslongTasks

The page has 5 CPU long tasks with the total of 492 ms. The total blocking time is 168 ms and 1 long task before first contentful paint with total time of 124 ms. However the CPU Long Task is depending on the computer/phones actual CPU speed, so you should measure this on the same type of the device that your user is using. Use Geckoprofiler for Firefox or Chromes tracelog to debug your long tasks.

Long CPU tasks locks the thread. To the user this is commonly visible as a "locked up" page where the browser is unable to respond to user input; this is a major source of bad user experience on the web today. However the CPU Long Task is depending on the computer/phones actual CPU speed, so you should measure this on the same type of the device that your user is using. To debug you should use the Chrome timeline log and drag/drop it into devtools or use Firefox Geckoprofiler.

Offenders
  • self
  • self
  • self
  • cross-origin-descendant
  • cross-origin-descendant
warn(0)Serve images in modern formats (AVIF, WebP)modernImageFormats

The page ships 72 images (out of 72) in JPEG/PNG/GIF without a modern alternative. Wrap them in a <picture> with a <source type="image/avif"> or "image/webp" before the legacy <img>, or serve modern formats from your image pipeline directly. AVIF and WebP usually deliver 25–50% smaller files at the same quality.

AVIF and WebP routinely deliver 25–50% smaller files than JPEG and PNG at the same perceived quality, and every browser version still under support understands at least one of them. Ship modern formats either through a <picture> element with <source type="image/avif"> / "image/webp" entries in front of the legacy <img>, or directly from a content-negotiating image pipeline that returns AVIF / WebP when the client accepts it. https://web.dev/articles/serve-images-webp

Offenders
infoAvoid too many fontsfewFonts
warn(0)Total JavaScript size shouldn't be too bigjavascriptSize

The total JavaScript transfer size is 605.5 kB and the uncompressed size is 1.5 MB. This is totally crazy! There is really room for improvement here.

A lot of JavaScript often means you are downloading more than you need. How complex is the page and what can the user do on the page? Do you use multiple JavaScript frameworks?

Offenders
URLTransferContent
https://www.google.com/recaptcha/api.js?hl=fr1011 B1.5 KB
https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js30.9 KB87.4 KB
https://www.proantic.com/js/sweetalert2.js15.0 KB47.2 KB
https://cdn.jsdelivr.net/npm/promise-polyfill@8/dist/polyfill.min.js2.2 KB4.3 KB
https://analytics.proantic.com/api/script.js33.5 KB33.2 KB
https://www.googletagmanager.com/gtag/js?id=G-YP51KSLLWR162.0 KB477.1 KB
https://www.gstatic.com/recaptcha/releases/zqB-6Xpbd3lCIvi7Tr2D0pob/recaptcha__fr.js346.8 KB829.4 KB
warn(50)Total image size shouldn't be too bigimageSize

The page total image size is 792.1 kB. It's really big. Is the page using the right format for the images? Can they be lazy loaded? Are they compressed as good as they can be? Make them smaller by using https://imageoptim.com/.

Avoid having too many large images on the page. The images will not affect the first paint of the page, but it will eat bandwidth for the user.

infoLong cache headers is goodcacheHeadersLong

The page has 45 requests that have a shorter cache time than one year (but still a cache time).

Setting a cache header is good. Setting a long cache header (a year) is even better because the asset will stay in the browser cache across visits. For content-hashed URLs (e.g. app.4af2.css) you can safely use Cache-Control: max-age=31536000, immutable. For unversioned URLs that may change, use a revalidating strategy instead.

Offenders
warn(58)Avoid slowing down the critical rendering pathavoidRenderBlocking

The page has 8 blocking requests and 3 in body parser blocking (4 JavaScript and 7 CSS). There are 2 potentially render blocking requests. You need to verify if they are render blocking: https://www.google.com/recaptcha/api.js?hl=fr https://www.googletagmanager.com/gtag/js?id=G-YP51KSLLWR

The critical rendering path is what the browser needs to do to start rendering the page. Every file requested inside of the head element will postpone the rendering of the page, because the browser need to do the request. Avoid loading JavaScript synchronously inside of the head (you should not need JavaScript to render the page), request files from the same domain as the main document (to avoid DNS lookups) and inline CSS for really fast rendering and a short rendering path.

Offenders
warn(70)Apply the right priority hints to the LCP imagelcpImageHints

The LCP image is missing fetchpriority="high". Adding it tells the browser to fetch the image with high priority instead of the default heuristic (which often deprioritises hero images that are loaded after the HTML has been parsed).

When the Largest Contentful Paint element is an image, the browser priority hints applied to that element directly affect the LCP metric. The image must NOT be loading="lazy" (that defers the fetch until near-viewport, which is the opposite of what an LCP image needs) and SHOULD be fetchpriority="high" (so the browser fetches it with high priority instead of guessing). https://web.dev/articles/fetch-priority

Offenders
  • <img onclick="carousel_center_open(event,this);" class="img_carousel" src="https://www.proantic.com/galerie/guillaumerullier/indexImage.jpg" alt="guillaumerullier-diapo-0">
warn(70)Avoid extra requests by setting cache headerscacheHeaders

The page has 3 requests that are missing a cache time. Configure a cache time so the browser doesn't need to download them every time. It will save 31.3 kB the next access.

The easiest way to make your page fast is to avoid doing requests to the server. Setting a cache header on your server response will tell the browser that it doesn't need to download the asset again during the configured cache time! Always try to set a cache time if the content doesn't change for every request.

Offenders
warn(80)Don't scale images in the browseravoidScalingImages

The page has 2 images that are scaled more than 100 pixels. It would be better if those images are sent so the browser don't need to scale them.

It's easy to scale images in the browser and make sure they look good in different devices, however that is bad for performance! Scaling images in the browser takes extra CPU time and will hurt performance on mobile. And the user will download extra kilobytes (sometimes megabytes) of data that could be avoided. Don't do that, make sure you create multiple version of the same image server-side and serve the appropriate one.

Offenders
infoMake each CSS response smalloptimalCssSize

https://www.proantic.com/css/A.sweetalert2-v1-2.css,,q202609211223+carrousel-09.css,,q202609211223+fontawesome.min.css,,q202609211223,Mcc.-ud7uC62EX.css.pagespeed.cf.cMgkAqLh5l.css size is 41.5 kB (41503) and that is bigger than the limit of 25 kB. https://www.gstatic.com/recaptcha/releases/zqB-6Xpbd3lCIvi7Tr2D0pob/styles__ltr.css size is 42.4 kB (42388) and that is bigger than the limit of 25 kB. Try to keep each CSS response under 25 kB.

Render-blocking CSS holds up the first paint until it has fully downloaded, parsed and applied, so smaller CSS files mean a faster start. Split your CSS into a small critical bundle inlined or eagerly loaded, with the rest lazy-loaded.

Offenders
URLTransferContent
https://www.proantic.com/css/A.sweetalert2-v1-2.css,,q202609211223+carrousel-09....cf.cMgkAqLh5l.css40.5 KB166.5 KB
https://www.gstatic.com/recaptcha/releases/zqB-6Xpbd3lCIvi7Tr2D0pob/styles__ltr.css41.4 KB81.0 KB
warn(80)Don't use private headers on static contentprivateAssets

The page has 2 requests with private headers. Make sure that the assets really should be private and only used by one user. Otherwise, make it cacheable for everyone.

If you set private headers on content, that means that the content are specific for that user. Static content should be able to be cached and used by everyone. Avoid setting the cache header to private.

Offenders
warn(90)Lazy-load below-the-fold imageslazyLoadingImages

The page has 6 below-the-fold images without loading="lazy". Add loading="lazy" so the browser defers downloading and decoding them until the user scrolls them into view.

Adding loading="lazy" to an <img> tells the browser not to download or decode it until it is close to the viewport. For images that the user may never see (deep in the page, behind a tab, in a footer carousel), this saves bandwidth and main-thread time during initial render. The LCP image and any image in the initial viewport should NOT be lazy-loaded — that delays the first paint. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#loading

Offenders
warn(90)Always compress text contentcompressAssets

The page has 1 request that are served uncompressed. You could save a lot of bytes by sending them compressed instead.

In the early days of the Internet there were browsers that didn't support compressing (gzipping) text content. They do now. Make sure you compress HTML, JSON, JavaScript, CSS and SVG. It will save bytes for the user; making the page load faster and use less bandwith.

Offenders
URLTransferContent
https://analytics.proantic.com/api/script.js33.5 KB33.2 KB

Best practice advice

91
1 warning2 info
infoAvoid unnecessary headersunnecessaryHeaders

There are 62 responses that sets both a max-age and expires header. There are 3 responses that sets a pragma no-cache header (that is a request header). There are 67 responses that sets a server header.

Do not send headers that you don't need. We look for p3p, cache-control and max-age, pragma, server and x-frame-options headers. Have a look at Andrew Betts - Headers for Hackers talk as a guide https://www.youtube.com/watch?v=k92ZbrY815c or read https://www.fastly.com/blog/headers-we-dont-want.

Offenders
warn(50)Avoid too many third party requeststhirdParty

The page do 15% requests to third party domains (10 requests and 671.5 kB). First party is 57 requests and 1.9 MB. The regex .*proantic.* was used to calculate first/third party requests.

Do not load most of your content from third party URLs.

infoDo not send too long headerslongHeaders

https://www.proantic...guillaumerullier/ has a header content-security-policy that is 2256 characters long.

Do not send response headers that are too long.

Offenders

Privacy advice

62
7 warnings4 info
warn(0)Declare a referrer policy on the documentreferrerPolicy

No <meta name="referrer"> tag was found on the page. Set a Referrer-Policy response header (preferred) or add a meta tag, for example <meta name="referrer" content="strict-origin-when-cross-origin">.

Without an explicit referrer policy the browser falls back to the user-agent default and may leak the full URL of the previous page (including query strings) to every cross-origin request. Set a Referrer-Policy response header (preferred) or a <meta name="referrer"> tag in the document. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Referrer-Policy

warn(0)Avoid embedding services from surveillance capitalist companiessurveillance

The page embeds 1 resource from companies that profit from user surveillance. Consider privacy-respecting alternatives.

Embedding scripts or iframes from companies whose business model is surveillance capitalism (Google, Facebook, etc.) leaks detailed user data on every page view, often before the user has had a chance to consent. See https://en.wikipedia.org/wiki/Surveillance_capitalism for background. Prefer privacy-respecting alternatives where possible.

Offenders
infoSet a Cross-Origin-Embedder-Policy header so cross-origin subresources opt in to being embedded.crossOriginEmbedderPolicyHeader

Set a Cross-Origin-Embedder-Policy header (typically require-corp or credentialless) on the document response to control cross-origin embedding.

Cross-Origin-Embedder-Policy (COEP) makes the page refuse to load cross-origin subresources unless they explicitly opt in via CORP or CORS. Together with Cross-Origin-Opener-Policy it puts the page in a cross-origin isolated context, which mitigates cross-window side-channel attacks (Spectre) and unlocks high-resolution timers and SharedArrayBuffer. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cross-Origin-Embedder-Policy

Offenders
warn(0)Set a Cross-Origin-Opener-Policy header to isolate the page from cross-origin windows.crossOriginOpenerPolicyHeader

Set a Cross-Origin-Opener-Policy header (typically same-origin) on the document response to isolate the page from cross-origin windows.

Cross-Origin-Opener-Policy (COOP) lets a page sever its window-group ties to cross-origin documents that opened it or that it opens. Together with Cross-Origin-Embedder-Policy it puts the page in a cross-origin isolated context, which mitigates cross-window side-channel attacks (Spectre) and unlocks high-resolution timers and SharedArrayBuffer. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cross-Origin-Opener-Policy

Offenders
infoSet a Cross-Origin-Resource-Policy header to limit who may embed the page.crossOriginResourcePolicyHeader

Set a Cross-Origin-Resource-Policy header (same-origin, same-site or cross-origin) on the document response to limit who may embed it.

Cross-Origin-Resource-Policy (CORP) is a per-response opt-in that tells the browser which origins are allowed to embed the resource. It blocks cross-origin or cross-site no-cors embedding (img, script, iframe, etc.) and is one of the building blocks of cross-origin isolation. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cross-Origin-Resource-Policy

Offenders
warn(0)Avoid using Google reCAPTCHAgoogleReCaptcha

You share your user data with Google since you use Google reCAPTCHA.

You should avoid using Google reCAPTCHA since it will share your users information with Google.

Offenders
infoSet a NEL header so the browser reports network errors back to you.nelHeader

Set a NEL header (paired with Reporting-Endpoints) to collect connection-level error reports from the field.

The NEL (Network Error Logging) response header tells the browser to record connection-level failures (DNS, TLS, HTTP errors) and ship them to a reporting endpoint. NEL pairs with the Reporting-Endpoints / Report-To header — the page declares the endpoint group and NEL points at it. Together they give you visibility into errors that never reach your origin server. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/NEL

Offenders
warn(0)Set a referrer-policy header to make sure you do not leak user information.referrerPolicyHeader

Set a referrer-policy header to make sure you do not leak user information.

Referrer Policy is a new header that allows a site to control how much information the browser includes with navigations away from a document and should be set by all sites. https://scotthelme.co.uk/a-new-security-header-referrer-policy/.

Offenders
infoDeclare reporting endpoints so the browser can deliver Reporting-API events.reportingEndpointsHeader

Set a Reporting-Endpoints header (or the legacy Report-To header) so CSP reports, NEL data and other Reporting-API events have an endpoint to land at.

The Reporting-Endpoints response header (the successor to Report-To) names the URLs that browsers should POST reports to. Without it, CSP report-to directives, Cross-Origin-Opener-Policy reports, NEL data and other Reporting-API events have nowhere to go. The legacy Report-To header is still accepted for older Chromium versions. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Reporting-Endpoints

Offenders
warn(0)Do not share user data with third parties.thirdPartyPrivacy

The page has 15% requests that are 3rd party (10 requests with a size of 671.5 kB). The page also have request to companies that harvest data from users and do not respect users privacy (see https://en.wikipedia.org/wiki/Surveillance_capitalism). The page do 3 utility requests and uses 1 utility tool. The page do 9 survelliance requests and uses 4 survelliance tools. The page do 9 surveillance requests and uses 4 surveillance tools. The page do 1 tag-manager request and uses 1 tag-manager tool.

Using third party requests shares user information with that third party. Please avoid that! The project https://github.com/patrickhulce/third-party-web is used to categorize first/third party requests.

Offenders
warn(30)Use a strict Content-Security-Policy header to mitigate cross-site scripting (XSS) attacks.contentSecurityPolicyHeader

The policy allows 'unsafe-inline', which lets the browser execute inline scripts and styles directly from the page. Move to nonces or hashes plus 'strict-dynamic' so that inline injection cannot run. The policy allows 'unsafe-eval', which lets the page call eval() and Function(). Almost no application needs this; remove it.

A Content-Security-Policy response header tells the browser which sources of script, style, and other content are allowed. The most effective form is a strict CSP using nonces or hashes together with strict-dynamic; the worst is a missing header, with unsafe-inline and unsafe-eval close behind. https://web.dev/articles/strict-csp

Page info

A snapshot of what the browser actually built for this page: the document, how big and deep the DOM tree is and what it kept in storage. Big, deep trees are slower to style and lay out, so the counts Chrome warns about carry a flag.

Page info

Document

What the page says it is and how large it rendered.

TitleProantic: Antiquités Expertise Guillaume RullierThe document title, shown in the browser tab and used by search results.
Layout viewport1350 × 5949 pxThe width the page laid out at, and the full height of the rendered document.

DOM structure

How much markup the browser has to build, style and lay out.

DOM elements1,498Very large, slows layout and styleTotal HTML elements. Fewer means less for the browser to style, lay out and paint.
Avg DOM depth8How deeply elements are nested on average.
Max DOM depth12The deepest nesting on the page. Deep branches cost more style recalculation.
Iframes3Embedded documents. Each is a separate page the browser loads and renders.
Script tags16Number of script elements. More scripts usually means more main-thread work.

Storage and connection

What the page stored on the client, and the network it was tested on.

Local storage53 BData the page saved in localStorage, kept across visits.
Session storage0 bData kept in sessionStorage for this tab session only.
Connection type4GWhat the Network Information API reported for the test connection.

Resource hints

2 hints
dns-prefetch
  • https://cdn-images.mailchimp.com/
preconnect
  • https://cdn-images.mailchimp.com/

Technologies used to build the page

Data collected using Coach-core version 9.2.1. With updated code from Webappanalyzer 2026-05-04. Use --browsertime.firefox.includeResponseBodies html or --browsertime.chrome.includeResponseBodies html to help Wappalyzer find more information about technologies used.

Detected technologies

5 technologies

Third-party tools

13 tools

Data collected using Third Party Web version 0.29.2.

Utility
  • Other Google APIs/SDKs
Survelliance
  • Other Google APIs/SDKs
  • Google CDN
  • Google Tag Manager
  • Google Fonts
Surveillance
  • Other Google APIs/SDKs
  • Google CDN
  • Google Tag Manager
  • Google Fonts
Cdn
  • Google CDN
  • JSDelivr CDN
  • Google Fonts
Tag-manager
  • Google Tag Manager

Data from run 1

Visual Metrics

Visual milestones

all times from navigation start
Speed Index0.88 show quickly the page looked done
First Visual Change0.60 sfirst paint reaches the screen
Last Visual Change1.48 sscreen stops changing · 0.87 s after first
nothing painted yet
≥85%
First Visual Change0.60 s
Visual Complete 85%1.31 s
Visual Complete 95% · Visual Complete 99% · Last Visual Change1.48 s
Visual Readiness0.87 s· first to last change
00.3 s0.5 s0.8 s1.0 s1.3 s
Visual progress
Visual progress at 0 s0.0s
Visual progress at 0.6 s0.6s
Visual progress at 0.7 s0.7s
Visual progress at 0.9 s0.9s
Visual progress at 1 s1.0s
Visual progress at 1.2 s1.2s
Visual progress at 1.3 s1.3s
Visual progress at 1.5 s1.5s
FCP0.58s
LCP0.72s
VC851.31s
Long tasks
0.0s0.3s0.6s0.9s1.2s1.5s

Google Web Vitals

from run 1

Largest Contentful Paint

When the page main content is rendered, collected via the Largest Contentful Paint API. Read more about Largest Contentful Paint.

720 msLCP render time

Phase breakdown

  • TTFB116 ms
  • Resource load delay14 ms
  • Resource load duration80 ms
  • Element render delay511 ms

Element

Element type
<img>
Size (w × h)
100825
URL
https://www.proantic...er/indexImage.jpg
Load time
704 ms
Style recalculation before LCP
10 recalculations touching 1276 elements (57.073 ms) — the largest touched 1253 elements (46.087 ms)

DOM path

body > main#detail > article#ddetail > div:eq(0) > div#slideshow-container > div:eq(1) > img
LCP

The LCP element is highlighted in the screenshot. If nothing is highlighted the element was removed before the screenshot or the LCP API couldn't find it.

The Largest Contentful Paint API matched this image:

LCP element

Cumulative Layout Shift

How much the page's content shifts as it loads, collected via the Cumulative Layout Shift API.

0.015cumulative layout shift score

One shift is 100% of your 0.015 CLS. div:eq(1) moved at 680 ms. Reserve space for whatever renders into that spot, a fixed height or an aspect-ratio box, so later content stops pushing the page around.

Elements that shifted

Worst first, showing shifts of 0.01 and up. Each percentage is that shift's exact share of the score.

  • 0.015
    100% of CLSshifted at 680 ms
    <div class="container-magindex-right">
    body > main#detail > article#ddetail > div:eq(1)
    body > main#detail > div:eq(0) > div > h1 > #text
    body > main#detail > div:eq(0) > div > div > #text
    <div class="w-dropdown-nav nav-menu-hover nav-menu-hover-meta">
    body > nav#totop > div > div > nav > div:eq(3)
    <div class="w-dropdown-nav nav-menu-hover nav-menu-hover-meta" data-menu="antiquaire">
    body > nav#totop > div > div > nav > div:eq(7)
Layout shift

Elements that shifted by more than 0.01 are highlighted in the screenshot. If an element shifted outside the viewport, it won't appear here. Check the video or filmstrip to see the shift.

Browser Metrics

Navigation Timing
Extra timings

Custom metrics collected through JavaScript

There are no custom configured scripts.

Extra metrics collected using scripting

There are no custom extra metrics from scripting.

Visual Elements3
LargestImageindexImage.jpg
Display time1.311 s
Position (x, y)50, 435
Size (w × h)544 × 338
HTML snippet
<img onclick="carousel_center_open(event,this);" class="img_carousel" src="https://www.proantic.com/galerie/guillaumerullier/indexImage.jpg" alt="guillaumerullier-diapo-0">
LargestImage preview
Heading
Display time740 ms
Position (x, y)10, 224
Size (w × h)1330 × 44
HTML snippet
<h1 class="h1-style h1-accueil toblur"></h1>
LargestContentfulPaintindexImage.jpg
Display time1.311 s
Position (x, y)50, 435
Size (w × h)544 × 338
HTML snippet
<img onclick="carousel_center_open(event,this);" class="img_carousel" src="https://www.proantic.com/galerie/guillaumerullier/indexImage.jpg" alt="guillaumerullier-diapo-0">
LargestContentfulPaint preview

PageXray

How the page is built.

HTTP versionHTTP/2.0
Total requests67
Total domains8
Transfer size2.5 MB
Content size3.9 MB
Missing compression1
Cookies10 third-party

Main document

status 200 · 0 redirects

https://www.proantic.com/galerie/guillaumerullier/

HeaderValue
cache-controlno-store, no-cache, must-revalidate max-age=0, no-cache, s-maxage=10
content-encodinggzip
content-security-policyupgrade-insecure-requests;font-src 'self' data:; img-src 'self' https://assets.pinterest.com/ https://www.googletagmanager.com https://*.googletagmanager.com/ https://*.google-analytics.com/ https://googleads.g.doubleclick.net https://stats.g.doubleclick.net data: blob:; frame-src 'self' https://www.youtube.com https://bid.g.doubleclick.net https://www.google.com/recaptcha/ https://recaptcha.google.com/recaptcha/; child-src 'self' https://www.google.com/recaptcha/ https://recaptcha.google.com/recaptcha/ ;connect-src 'self' https://analytics.proantic.com/ https://storage.googleapis.com/monocle-spdj-production.appspot.com/ wss://gallery-rc.monocle3d.com wss://gallery.monocle3d.com https://gallery-rc.monocle3d.com/ https://components-rc.monocle3d.com/ https://gallery.monocle3d.com/ https://components.monocle3d.com/ https://www.google.com/recaptcha/api2/ https://firebasestorage.googleapis.com https://firestore.googleapis.com https://*.analytics.google.com https://*.googletagmanager.com https://*.google-analytics.com/ https://www.google-analytics.com/j/ www.google-analytics.com *.google-analytics.com https://stats.g.doubleclick.ne blob:; form-action 'self' https://www.sandbox.paypal.com/ https://www.paypal.com/ https://proantic.us8.list-manage.com/subscribe/post; object-src 'none'; worker-src 'self' blob:; base-uri 'self'; frame-ancestors 'self';script-src 'unsafe-eval' 'unsafe-inline' 'self' https://analytics.proantic.com/api/script.js https://components.monocle3d.com/ https://components-rc.monocle3d.com/ https://www.googletagmanager.com/ https://monocle.link https://monocle.link/ https://ajax.googleapis.com/ajax/libs/model-viewer/3.5.0/model-viewer.min.js https://cse.google.com/cse/ https://www.google.com/cse/ https://tagmanager.google.com https://transloadit.edgly.net/releases/ https://code.jquery.com/jquery-3.2.1.min.js https://cdn.jsdelivr.net/npm/ https://apis.google.com/ajax/libs/ https://www.google.com/recaptcha/api.js https://ajax.googleapis.com/ajax/libs/webfont/ https://apis.google.com/js/ https://ajax.googleapis.com/ajax/libs/jquery/ https://ajax.googleapis.com/ajax/libs/jqueryui/ https://www.gstatic.com/recaptcha/ https://cdnjs.cloudflare.com/ajax/libs/jquery/ https://cdnjs.cloudflare.com/ajax/libs/jqueryui/;
content-typetext/html; charset=utf-8
dateWed, 23 Sep 2026 01:34:54 GMT
expiresThu, 19 Nov 1981 08:52:00 GMT
permissions-policygeolocation=(self), microphone=()
pragmano-cache
servernginx
strict-transport-securitymax-age=63072000; includeSubDomains; preload
varyAccept-Encoding
x-content-type-optionsnosniff
x-frame-optionsSAMEORIGIN
x-mod-pagespeed1.13.35.2-0

Response codes

200
6698.5%
204
11.5%

Requests and sizes per content type

7 types

Transfer size2.5 MB

  • font38.1%
  • image31.1%
  • javascript23.4%
  • css4.7%
  • html2.7%
  • json0.03%

Content size3.9 MB

  • javascript37.2%
  • font24.0%
  • image19.4%
  • css10.8%
  • html8.6%
  • json0.01%

Requests67

  • image49.3%
  • font19.4%
  • css11.9%
  • javascript10.4%
  • html4.5%
  • json3.0%
  • other1.5%
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b68.1 KB340.8 KB3
css0 b118.1 KB431.7 KB8
javascript0 b591.3 KB1.4 MB7
image0 b784.4 KB773.6 KB33
font0 b962.0 KB957.5 KB13
json0 b701 B287 B2
other0 b0 b0 b1
Total0 b2.5 MB3.9 MB67

Data per domain

8 domains
DomainTotal download timeTransfer SizeContent SizeRequests
www.proantic.com6.727 s1.8 MB2.3 MB53
www.google.com100 ms31.1 KB71.7 KB3
ajax.googleapis.com39 ms30.9 KB87.4 KB1
cdn.jsdelivr.net39 ms2.2 KB4.3 KB1
analytics.proantic.com240 ms34.2 KB33.5 KB4
www.googletagmanager.com983 ms162.0 KB477.1 KB1
www.gstatic.com1.308 s390.4 KB912.6 KB3
fonts.gstatic.com125 ms39.2 KB39.2 KB1

Expires & last-modified statistics

typeminmedianmax
Expires0 seconds4 weeks1 year
Last modified2 days13 weeks17 years

Requests loaded after onLoad event

2 requests

Includes requests done after load event end.

ContentTransfer SizeRequests
html2.2 KB1
css0 b0
javascript0 b0
image3.3 KB1
font0 b0
favicon0 b0
Total5.5 KB2

Requests loaded after onContentLoad

8 requests

Includes requests done after DOM content loaded.

ContentTransfer SizeRequests
html30.1 KB2
css41.4 KB1
javascript0 b0
image5.5 KB2
font39.2 KB1
favicon0 b0
other0 b1
json222 B1
Total116.4 KB8

CPU

Long tasks

Tasks ≥ 50 ms blocking the main thread, collected via the Long Task API.

TBT168 ms
Max potential input delay121 ms
Total long tasks5
Total time492 ms
Last task at2.219 s
Before first paint124 ms1 task
Before FCP124 ms1 task
Before LCP124 ms1 task
After load69 ms1 task

Long Animation Frames

A long animation frame (LOAF) is a frame that took ≥ 50 ms from input to the next paint. The part beyond the threshold is blocking time, the number that hurts Interaction to Next Paint and Total Blocking Time. Break long tasks up (scheduler.yield(), smaller chunks) or move the work off the main thread. Read more about the Long Animation Frames API.

Long animation frames7every frame ≥ 50 ms
Blocking time184.1 msacross all long frames — what hurts INP and TBT
Forced style & layout15.3 msscripts reading layout mid-frame
Blocking before LCP72.9 msdelaying the largest paint — fix these first
Blocking after load19.8 msafter the load event — didn't delay page load

What to fix first

ScriptFramesTime runningBlocking (share by run time)Forced style & layoutTriggered by
recaptcha__fr.js3rd party1121.1 ms71.5 ms0.6 msscript tag
js3rd party169.7 ms19.8 ms–script tag
inline script in the document117.7 ms0 ms14.7 msscript tag

A frame's blocking time is split between its scripts by their share of the frame's work, capped at each script's own run time — blocking from work no script owns (HTML parsing, browser internals) stays unattributed. The per-script blocking view below uses the same attribution.

Long animation frame #1 · 398.6 msat 135.9 ms · before LCP
blocking 72.9 ms
  • Scripts & other work286.9 ms
  • Animation callbacks0.3 ms
  • Style & layout111.4 ms
  • Render0 ms

The browser did not report which script was responsible for this frame — typically its own style/layout work, or a cross-origin script it will not name.

Long animation frame #2 · 121.7 msat 1.486 s · before load
blocking 71.6 ms
  • Scripts & other work121.3 ms
  • Animation callbacks0 ms
  • Style & layout0.4 ms
  • Render0 ms
1 script ran during this frame · forced style & layout 0.6 ms
Ran for
121.1 ms
Forced style and layout
0.6 ms
How it started
script tag
Long animation frame #3 · 69.8 msat 1.142 s · before load
blocking 19.8 ms
  • Scripts & other work69.8 ms
  • Animation callbacks0 ms
  • Style & layout0 ms
  • Render0 ms
1 script ran during this frame
js3rd party
Ran for
69.7 ms
How it started
script tag
Long animation frame #4 · 71.2 msat 2.218 s · after load
blocking 19.8 ms
  • Scripts & other work70.8 ms
  • Animation callbacks0.4 ms
  • Style & layout0 ms
  • Render0 ms

The browser did not report which script was responsible for this frame — typically its own style/layout work, or a cross-origin script it will not name.

3 more long frames carried no blocking time (nothing ran past the 50 ms threshold) — long, but harmless to INP and TBT.

Blocking time per script (browser-reported)

How much each script blocked the main thread, derived from the Long Animation Frame API. Each frame's blocking time is split between its scripts by their share of the frame's work, capped at each script's own run time — blocking from work no script owns (HTML parsing, browser internals) is not attributed (older data credits the script that started the frame). The closest answer to "which script should I fix to improve TBT" the platform exposes.

Top scripts blocking the main thread

2 of 2 scripts

Blocking time per script (trace)

Total Blocking Time attributed per script from the Chrome trace: every main-thread task longer than 50 ms blocks input for the remainder, and each blocking task is credited to the script whose own code ran the longest during that task.

TBT246.3 ms
Blocking tasks5
TBT before LCP75.9 ms1 task

What kind of work blocked

mostly running javascript · 246 ms total
Running JavaScript166.2 ms67.5%
Style & layout68.2 ms27.7%
Paint & composite5.9 ms2.4%
Other browser work2.8 ms1.1%
Garbage collection1.6 ms0.6%
Parsing HTML & CSS1.5 ms0.6%
Parsing & compiling JavaScript0.1 ms0.0%
Running JavaScript (67%): the scripts responsible are listed right below. See Timers
Style & layout (28%): usually a large DOM, expensive CSS selectors or JavaScript forcing synchronous layout. See Forced reflows · Forced layout per script · Style invalidations (Rendering tab)

Where the time went

All main-thread work during the full page load, not just the share that blocked input. Calculated from the Chrome trace.

Categories

1.394 s total
Running JavaScript892 ms64.0%
Style & layout179 ms12.8%
Other browser work (scheduling)162 ms11.6%
Parsing HTML & CSS81 ms5.8%
Paint & composite46 ms3.3%
Garbage collection18 ms1.3%
Parsing & compiling JavaScript16 ms1.1%
What do these categories mean?
Parsing HTML & CSSparseHTML
Reading the HTML and CSS and building the page structure. Grows with document size — a big server-rendered page costs more here.
Style & layoutstyleLayout
Working out which CSS rules apply and where every element goes on the page. Grows with DOM size and selector complexity.
Parsing & compiling JavaScriptscriptParseCompile
Parsing and compiling JavaScript before it can run — the cost of shipping bytes of JS, even unused ones.
Running JavaScriptscriptEvaluation
Running JavaScript: event handlers, timers, promise callbacks and script execution.
Paint & compositepaintCompositeRender
Painting pixels and assembling layers into the frames you see on screen.
Garbage collectiongarbageCollection
Reclaiming memory JavaScript no longer uses. A lot of it means allocation-heavy code.
Other browser work (scheduling)other
Chrome’s own task management: per-task overhead and thousands of sub-millisecond scheduler ticks — not page work you can attribute or optimize away. On this page 161 ms of it is this per-task bookkeeping (RunTask self time in the trace).

CPU time per script

Timers

How much setTimeout/setInterval work the page runs, credited to the script that scheduled each timer. Many zero-delay timers mean work sliced into a machine-gun of tiny tasks; repeating timers are polling.

Timers set208
Times fired298
Fire time177.2 ms
Zero-delay timers28
Repeating timers2
Polling: Q0.l.t.<computed>.Q0.aU in https://www.gstatic.com/recaptcha/releases/zqB-6Xpbd3lCIvi7Tr2D0pob/recaptcha__fr.js keeps a 100 ms timer running: it fired 108 times costing 31 ms. Consider reacting to events instead, or a longer interval.
Zero-delay slicing: kd in https://www.googletagmanager.com/gtag/js?id=G-YP51KSLLWR split work into 22 back-to-back tasks costing 3 ms. Consider batching the work or moving it to requestIdleCallback or a worker.

Timer cost by script

5 scripts
Unknown script
163 ms · set 0 times · fired 152 times
https://www.googletagmanager.com/gtag/js?id=G-YP51KSLLWR
3 ms · set 23 times · fired 14 times
https://www.proantic.com/galerie/guillaumerullier/
0 ms · set 1 time · fired 0 times

Forced reflows

A forced reflow happens when JavaScript reads a layout-triggering property (offsetTop, getBoundingClientRect, …) inside a handler, forcing the browser to synchronously recompute layout. The scripts below caused most of the page's reflows. Fix them in priority order.

Scripts causing reflows

4 reflows ≥ 2 ms across 3 scripts

Forced layout per script

Each long animation frame reports how much time each script spent forcing synchronous style and layout, i.e. JavaScript reading layout-triggering properties mid-execution. Same actionable answer as forced reflows above but measured directly by the browser instead of inferred from the trace.

Scripts forcing layout

1 of 2 scripts
inline script in the document
15 ms · across 1 frame

First vs third party CPU time

Main-thread CPU time from the Chrome trace split by domain. First party is proantic.com.

First party32 ms
Third party649 ms
Domains5

CPU time per domain/tool

Domain / tool breakdown

4 entities
Google CDN
500.9 ms
Google Tag Manager
94.5 ms
Other Google APIs/SDKs
44.4 ms
www.proantic.com
23.6 ms

Want to dig deeper? Download the Chrome trace and drag-and-drop it into Performance in DevTools.

Third party

Third party requests categorised by Third party web version 0.29.2.

Third-party requests19
Tools5
Categories4

Categories

4 categories

Requests by category19

  • survelliance9 req · 4 tools47.4%
  • cdn6 req · 3 tools31.6%
  • utility3 req · 1 tool15.8%
  • tag-manager1 req · 1 tool5.3%

Third party requests and tools

4 categories
utilityOther Google APIs/SDKs3 requests · 1 tool
survellianceOther Google APIs/SDKsGoogle CDNGoogle Tag Manager+ 1 more9 requests · 4 tools
cdnGoogle CDNJSDelivr CDNGoogle Fonts6 requests · 3 tools
tag-managerGoogle Tag Manager1 requests · 1 tool

First party vs third party

57 first · 10 third party

Transfer size2.5 MB

  • First party1.8 MB74.0%
  • Third party655.7 KB26.0%

Content size3.9 MB

  • First party2.3 MB60.0%
  • Third party1.6 MB40.0%

Requests67

  • First party5785.1%
  • Third party1014.9%

First party requests and sizes per content type

57 requests

Calculated using .*proantic.* (use --firstParty to configure).

ContentHeader SizeTransfer SizeContent SizeRequests
html0 b38.0 KB270.6 KB1
css0 b76.7 KB350.7 KB7
javascript0 b48.5 KB80.4 KB2
image0 b782.2 KB771.4 KB32
font0 b922.8 KB918.3 KB12
favicon0 b0 b0 b0
json0 b701 B287 B2
other0 b0 b0 b1
TotalN/A1.8 MB2.3 MB57

Third party requests and sizes per content type

10 requests
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b30.1 KB70.2 KB2
css0 b41.4 KB81.0 KB1
javascript0 b542.8 KB1.4 MB5
image0 b2.2 KB2.2 KB1
font0 b39.2 KB39.2 KB1
favicon0 b0 b0 b0
TotalN/A655.7 KB1.6 MB10

Axe

Axe is an accessibility testing engine for websites and other HTML-based user interfaces. Tested using axe-core version 4.11.4. Read more about axe-core.

This page has accessibility issues to fix.

Worst impact across the runs: serious. Open an individual run to see the actual violations.

Violations

median across runs
Critical00 issues
Serious26 issues
Moderate25 issues
Minor00 issues