www.firefox.com speed test — 20 Oct 2026

Measured from the wfix.shop server on 20 October 2026 at 12:24 UTC. Grade A (95/100), with the screenshots, the timings and the fixes that matter.

https://www.firefox.com/

20 October 2026 at 12:24 UTC · Free test · report pt_51c37ccc705e
Grade
A
95/100
Performance99/100
Structure89/100

14 audit(s) passed, 2 need work

First byte (TTFB)247 msmeasured from this server
Fully loaded813 msfirst byte + slowest asset
Requests18document + assets
Page weight103.2 KBcompressed transfer
HTML document7.7 KBbr
ProtocolHTTP/3granian

Where the first byte went

  • DNS lookup 34 ms 14%
  • TCP connect 13 ms 5%
  • Server wait 200 ms 81%

Measured on the connection that fetched the HTML. Every other request on the page waits for the end of this bar before it can start.

How this page compares

First bytefaster than 85% of 4,999 pages tested here247 ms against a median of 449 ms
Page weightlighter than 87% of 4,999 pages tested here103.2 KB against a median of 650.5 KB
Fully loadedfaster than 95% of 4,999 pages tested here813 ms against a median of 1.84 s
Requestssends fewer requests than 81% of 4,999 pages tested here18 against a median of 26

Every report published here is in this comparison, so it is a reference population of pages tested from one server - not a benchmark of the whole web.

What these numbers mean

  • The first byte arrived in 247 ms. That is workable, and the cheapest win left is caching or a warmer connection.
  • The page transfers 103.2 KB over 18 request(s). Javascript files are 55% of it, so defer what is not needed for the first screen, and drop tags nobody uses.
  • The HTML itself arrives br-compressed.
  • It runs over HTTP/3, so the assets share a connection instead of opening one each.
  • The largest element painted at 564 ms, inside the 2.5 s Google calls good.
  • Layout stayed still (CLS 0.093), so nothing jumps under the reader's cursor.
  • The main thread was blocked for 260 ms, so taps and scrolling wait while scripts run.

Fix first: Render-blocking resources - Add defer or async to scripts that do not change the first paint, inline the critical CSS, and load the rest with media="print" plus an onload swap.

Read on one shared server, not a visitor's phone: use it to compare pages against each other, not as a promise about every connection. We fix what these tests find.

Screenshot

What the page looks like

Loaded in headless Chromium on this server. Click an image to open it full size.

Mobile screenshot of www.firefox.com
Mobile 390 × 844 · 39.5 KB · page is 5505 px tall

Browser render

The same URL loaded in a real browser, so these are the readings curl cannot produce. The grade above is still built from the server measurements.

Largest contentful paint564 msgood is under 2.5 s
Cumulative layout shift0.093under 0.1 is stable
Total blocking time260 mslong tasks during load
First contentful paint564 msfirst content on screen
Browser page weight705.8 KB30 request(s), scripts included
Largest contentful paint564 ms
Goodgood under 2.5 s, poor over 4 s
Cumulative layout shift0.093
Goodgood under 0.1, poor over 0.25
Total blocking time260 ms
Needs improvementgood under 200 ms, poor over 600 ms

Page weight by type

What the page is made of

Javascript 10 requests
56.2 KB 55%
Images 5 requests
25.9 KB 25%
Css 2 requests
13.3 KB 13%

Transfer size, compressed as sent. 18 request(s) in total, 103.2 KB across all of them.

Top issues

Render-blocking resources

high impact

7 render-blocking resource(s) in the document head (4 script(s), 3 stylesheet(s)). The page cannot paint until each one arrives.

Fix: Add defer or async to scripts that do not change the first paint, inline the critical CSS, and load the rest with media="print" plus an onload swap.

Avoid extra redirects

medium impact

1 redirect hop(s) before the page load started, each one a full round trip before the first byte.

Fix: Link to the canonical URL (and make sure http, the apex domain and www all point at it) so no visitor pays a redirect first.

Waterfall

Slowest requests

CSSwww.firefox.com/media/css/protocol.6e35a2b1be5a.css
566 ms
CSSwww.firefox.com/media/css/locales.e00481260096.css
564 ms
IMAGESwww.firefox.com/media/img/favicons/firefox/browser/fav…
557 ms
IMAGESwww.firefox.com/media/img/favicons/firefox/browser/fav…
556 ms
JAVASCRIPTwww.firefox.com/media/js/site.500a27b182b4.js
554 ms
JAVASCRIPTwww.firefox.com/media/js/data.ae7988941297.js
553 ms
JAVASCRIPTwww.firefox.com/media/js/mobile-attribution.1024b5f1ff…
553 ms
JAVASCRIPTwww.firefox.com/media/js/fxa.6bf27a1d1632.js
553 ms
JAVASCRIPTwww.firefox.com/media/js/consent-banner.40c6bdf0d75c.js
552 ms
JAVASCRIPTwww.firefox.com/media/js/ui.0564ca2e7049.js
550 ms

Each bar is one request's own response time, scaled to the slowest. Assets were fetched in parallel, so the bars overlap in real time rather than stacking. first party third party

RequestTypeStatusTimeSize
https://www.firefox.com/media/css/protocol.6e35a2b1be5a.csscss200566 ms12.8 KB
https://www.firefox.com/media/css/locales.e00481260096.csscss200564 ms552 B
https://www.firefox.com/media/img/favicons/firefox/browser/favicon.f093404c0135.icoimages200557 ms7.7 KB
https://www.firefox.com/media/img/favicons/firefox/browser/favicon-196x196.59e3822720be.pngimages200556 ms7.9 KB
https://www.firefox.com/media/js/site.500a27b182b4.jsjavascript200554 ms2.4 KB
https://www.firefox.com/media/js/data.ae7988941297.jsjavascript200553 ms5.0 KB
https://www.firefox.com/media/js/mobile-attribution.1024b5f1ffe0.jsjavascript200553 ms736 B
https://www.firefox.com/media/js/fxa.6bf27a1d1632.jsjavascript200553 ms679 B
https://www.firefox.com/media/js/consent-banner.40c6bdf0d75c.jsjavascript200552 ms4.9 KB
https://www.firefox.com/media/js/ui.0564ca2e7049.jsjavascript200550 ms6.7 KB
https://www.firefox.com/media/js/download-attribution-init-essential.57308ca7bf9d.jsjavascript200550 ms3.3 KB
https://www.firefox.com/media/img/icons/m24-small/download-white.81646af3f50d.svgimages200547 ms219 B
https://www.firefox.com/media/img/favicons/firefox/browser/apple-touch-icon.79c2abeb4e35.pngimages200546 ms7.0 KB
https://www.firefox.com/media/img/logos/firefox/logo-word-hor.f3b18871b657.svgimages200544 ms3.1 KB
https://www.firefox.com/media/js/lib.559a10bc3b5a.jsjavascript200541 ms4.9 KB
https://www.firefox.com/media/js/sentry.d58326051ba8.jsjavascript200540 ms23.6 KB
https://www.firefox.com/media/js/gtm-snippet.df0de58306e0.jsjavascript200540 ms4.0 KB
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