Free Browser Compatibility Test for Modern Web Features and APIs
Check a broad set of modern browser features with live feature detection, category scores, environment details, filters, and a downloadable compatibility report.
Browser Compatibility Test for Modern Web Features and APIs
| Category | Feature | Supported | Detection |
|---|
Built for a complete diagnostic workflow
30+ live feature checks
Browser Feature Compatibility Checker workflow feature designed for practical browser use.
CSS feature detection with CSS.supports
Browser Feature Compatibility Checker workflow feature designed for practical browser use.
JavaScript API detection
Browser Feature Compatibility Checker workflow feature designed for practical browser use.
Storage capability checks
Browser Feature Compatibility Checker workflow feature designed for practical browser use.
Media API checks
Browser Feature Compatibility Checker workflow feature designed for practical browser use.
Graphics API checks
Browser Feature Compatibility Checker workflow feature designed for practical browser use.
Worker and observer checks
Browser Feature Compatibility Checker workflow feature designed for practical browser use.
Secure-context status
Browser Feature Compatibility Checker workflow feature designed for practical browser use.
Viewport, DPR, touch and language report
Browser Feature Compatibility Checker workflow feature designed for practical browser use.
Category filtering
Browser Feature Compatibility Checker workflow feature designed for practical browser use.
Compatibility score
Browser Feature Compatibility Checker workflow feature designed for practical browser use.
Copyable JSON-style summary
Browser Feature Compatibility Checker workflow feature designed for practical browser use.
How to interpret this browser feature compatibility checker
A browser compatibility test should detect capabilities instead of relying only on a browser name or version. Feature detection asks whether the current environment actually exposes the API or CSS capability that a site needs.
This checker groups capabilities across layout, JavaScript, storage, media, graphics, device access, observers, workers, and user-interface APIs. A supported result means the browser exposes the tested entry point; it does not guarantee every edge case or subfeature works identically.
Secure-context requirements matter for many modern APIs. A feature may exist in the browser but remain unavailable to a page served from an untrusted context, embedded with restrictive permissions, or blocked by policy.
Use the export as a troubleshooting snapshot. For production compatibility decisions, test the exact workflow and consult the relevant standards or authoritative browser-compatibility data for the specific feature version you depend on.
What the browser can and cannot tell you
| Signal | What it represents | How to use it |
|---|---|---|
| CSS.supports | Checks parsed CSS capability | Good for layout and property features |
| API existence | Checks objects/functions on the current page | Fast but may not cover every subfeature |
| Secure context | Reports isSecureContext | Important for media, clipboard, and device APIs |
| Permission-sensitive APIs | May exist before permission is granted | Support does not imply user permission |
| Experimental APIs | Can vary by browser release | Always pair detection with fallback behavior |
Build a better troubleshooting habit
Start with a baseline
Run the primary diagnostic before changing settings so you have a comparison point.
Repeat the test
One sample can be misleading. Repeat the check and compare the pattern, not only the best number.
Change one variable
When troubleshooting, change one device, browser, permission, cable, or setting at a time.
Separate browser from hardware
A browser result reflects only the parts of the input or output path that the page can observe.
Document the environment
Keep browser, operating system, device connection, scaling, or permission context with the result.
Use the next diagnostic
Open a related ready page when the result suggests a neighboring part of the device or browser stack.
Three quick questions
Finish with a quality review
Recent saved milestones on this device
Continue without a dead end
Free Browser Compatibility Test for Modern Web Features and APIs: FAQ
Does a supported result guarantee the feature is bug-free?+
No. It confirms the tested capability is exposed or parsed, not that every edge case behaves identically.
Is user-agent sniffing used?+
The main score is based on feature detection. Environment details may include the user-agent string only as contextual information.
Why does an API show supported but still fail in my app?+
Permissions, secure-context requirements, sandboxing, policy, device availability, or missing subfeatures can still block actual use.
Can I use this to decide whether to drop an old browser?+
It is a useful snapshot, but production decisions should also consider your analytics, target audience, exact feature requirements, and fallback strategy.
Does the test send my browser details anywhere?+
No. The detection and report are generated in the page.
Use the result responsibly
This tool reports what a browser can observe or calculate in the current environment. Device firmware, drivers, operating-system processing, permissions, transport, display refresh, acoustic conditions, and browser implementation can add behavior that this page cannot isolate.
External technical reference: MDN: Implementing feature detection ↗.