Check browser support for modern CSS features. Test Flexbox, Grid, Container Queries, View Transitions and more. | No Signup, Client-Side · No Server Uploads
Zero Dependencies·Works OfflineCSS evolves rapidly with new features being added regularly. Different browsers implement CSS features at different speeds. This tool uses the native CSS.supports() API to instantly check your browser support for 80+ modern CSS features.
Open the tool to see 8 categories of CSS features. Click any feature to test browser support, or click "Test All" to run a complete check. Use the search box to find specific properties, or enter custom CSS declarations for testing.
The CSS.supports() API is part of the CSS Conditional Rules Module. It accepts CSS.supports(property, value) or CSS.supports(declaration) syntax and returns true if the browser supports the CSS declaration, false otherwise.
It uses the browser native CSS.supports() API - no external resources needed, results are 100% accurate.
80+ modern CSS features across 8 categories: Layout, Animation, Color, Typography, Effects, Selectors, UI Components, and New Features.
CSS.supports() is a native browser API. Results accurately reflect your current browser actual support.
Yes! Use the "Custom Test" feature to enter any CSS declaration and check browser support.
No. All tests run completely in your browser - no network requests, no data upload.