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Web-PSQC
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Cross-browser compatibility test

Make sure your site works for visitors on Chrome, Edge, Firefox and Safari, not only in the browser you build with. This test opens your page in the three major browser engines, Chromium, Firefox (Gecko) and WebKit, and compares whether it loads, which JavaScript errors appear and how much content each engine renders. A screenshot from each engine shows rendering differences at a glance.

Runs only this test. Want everything? Run all 18 tests from the home page.

What this test checks

Loads in each engine

Whether the page opens in Chromium, Firefox and WebKit with an HTTP status below 400.

JavaScript errors

Console errors and uncaught exceptions from your own code in each engine, with errors from third-party scripts counted separately.

Rendered content

Text length and page height in Firefox and WebKit compared with Chromium, which reveals sections that fail to render.

CSS warnings

CSS declarations and rules an engine reports as dropped or unparsable, shown for reference and not scored.

Screenshots

A screenshot from each engine for a quick side-by-side visual check.

Sample result

A real result for devteam.co.kr, tested 3 hours ago.

Browser compatibility

Works cleanly in 3 of 3 browser engines (Chromium, Firefox, WebKit).

100/100A+
Works in Chrome / Edge (Chromium) (Good)
Loads and renders without script errors in Chrome / Edge (Chromium).
720 ms · 0 JS errors
Target: Loads, renders the same content, no script errors
Works in Firefox (Gecko) (Good)
Loads and renders without script errors in Firefox (Gecko).
800 ms · 0 JS errors
Target: Loads, renders the same content, no script errors
Works in Safari (WebKit) (Good)
Loads and renders without script errors in Safari (WebKit).
2.3 s · 0 JS errors
Target: Loads, renders the same content, no script errors
Chrome / Edge (Chromium) screenshot
Chrome / Edge (Chromium)
720 ms · 0 JS errors · 4,600 chars
Firefox (Gecko) screenshot
Firefox (Gecko)
800 ms · 0 JS errors · 4,600 chars
Safari (WebKit) screenshot
Safari (WebKit)
2.3 s · 0 JS errors · 4,600 chars

How it works

  1. Playwright opens your page in Chromium, Firefox and WebKit, one after another, on our test server in Virginia, USA.
  2. Each engine uses a 1280×800 desktop window, waits for the load event (up to 40 seconds) and then up to 5 more seconds for network activity to settle.
  3. WebKit is the open-source engine behind Safari, so it shows how Safari users on Mac and iPhone are likely to see the page.
  4. Every request goes through a network guard that only connects to public IP addresses on ports 80 and 443.
  5. The three runs typically take about 70 seconds in total.

How it is scored

The score uses our item-weighted formula: each engine earns full credit for a pass, half for a warning and none for a fail, with Chromium and WebKit weighted 3× and Firefox 2×. Grades follow our scale: A+ 95+, A 90+, B 80+, C 70+, D 60+, F below 60.

CheckGoodNeeds workPoor
Page loadsHTTP status below 400—Error, timeout or status 400+
JavaScript errors from your own codeNone1–23 or more
Content compared with ChromiumSimilar text and page heightUnder 70% of the text or 60% of the height—

Grades: A+ 95–100 · A 90–94 · B 80–89 · C 70–79 · D 60–69 · F below 60.

FAQ

How do I test my website in different browsers?
Enter your URL and run this test. It opens the page in Chromium (Chrome and Edge), Firefox and WebKit (Safari's engine), reports JavaScript errors and missing content in each, and shows a screenshot from every engine.
Can I test Safari without a Mac?
Yes, for a first check. This test uses Playwright's WebKit build, the open-source engine Safari is built on, so most Safari-specific layout and JavaScript problems show up here. For a final sign-off, confirm on a real Mac or iPhone.
Why does my site work in Chrome but not in Safari or Firefox?
The usual causes are JavaScript or CSS features one engine does not support yet, browser-specific code, and a failing script that stops the rest of the page from running. The report shows up to five JavaScript errors per engine, so you can reproduce them and add a fallback or polyfill.
Do errors from third-party scripts affect the score?
No. Console errors from scripts on other domains, such as ads, chat widgets or analytics, are counted separately and do not change the score. Uncaught exceptions are always counted, because they can stop your own code from running.