Test your browser's support for modern web technologies with our comprehensive feature detection tool. Instantly check compatibility for WebGL, WebRTC, Service Workers, IndexedDB, Web Audio, WebAssembly, and 50+ other web APIs. Essential for web developers, QA testers, and anyone verifying browser capabilities.
Browser feature support testing determines which modern web APIs, technologies, and standards your browser can utilize. Different browsers implement features at different rates, with some supporting cutting-edge APIs while others lag behind. Testing feature support helps developers ensure compatibility, enables progressive enhancement strategies, and identifies browser limitations. This tool checks over 50 critical web platform features across seven categories.
WebGL enables hardware-accelerated 3D graphics in browsers without plugins, powering everything from games to data visualizations. WebGL2 adds advanced rendering capabilities like 3D textures, transform feedback, and improved shader support. Most modern browsers support WebGL, but older devices or browsers may lack WebGL2. These APIs enable applications like Three.js 3D scenes, WebGL games, interactive maps, and GPU-accelerated computing through fragment shaders.
Web Real-Time Communication enables peer-to-peer audio, video, and data sharing directly between browsers without servers. WebRTC powers video conferencing apps like Google Meet and Discord, enables screen sharing, facilitates file transfers, and supports real-time gaming. Implementation varies across browsers, with Safari historically lagging but now offering solid support. WebRTC requires HTTPS for security and works best with TURN/STUN servers for NAT traversal.
The Web Audio API provides sophisticated audio processing and synthesis capabilities, far exceeding basic HTML5 audio elements. It enables spatial audio, real-time effects processing, audio visualization, synthesis, and precise timing control. Use cases include music production apps, games with 3D audio, podcasting tools, and audio analysis. The API uses a node-based architecture where audio sources, effects, and destinations connect in processing graphs.
WebXR enables virtual reality and augmented reality experiences in browsers, accessing VR headsets and AR capabilities. It replaces the deprecated WebVR API with more robust AR support. WebXR allows immersive 3D experiences, AR product visualization, virtual tours, and training simulations. Support is best in Chrome and Edge, limited in Firefox, and unavailable in Safari. WebXR requires HTTPS and user permission for device access.
These simple key-value storage APIs persist data locally. localStorage stores data permanently until explicitly cleared, while sessionStorage clears when the browser tab closes. Both offer 5-10MB storage per domain and work synchronously. Use cases include saving user preferences, form data, shopping carts, and session tokens. However, localStorage is synchronous and can block the main thread, so IndexedDB is preferred for large datasets.
IndexedDB is a powerful transactional database system for storing significant amounts of structured data, including files and blobs. It offers hundreds of megabytes to gigabytes of storage depending on browser and available disk space. IndexedDB uses an asynchronous API preventing UI blocking, supports transactions for data consistency, enables complex queries with indexes, and works offline. It's ideal for offline-first applications, caching large datasets, and progressive web apps.
The Cache API enables programmatic control over cached resources, primarily used with Service Workers for offline functionality. It stores network requests and responses, enabling instant loading even without connectivity. Cache API powers progressive web apps, reduces bandwidth usage, improves performance, and enables sophisticated caching strategies like cache-first, network-first, or stale-while-revalidate. Unlike HTTP cache, developers have precise control over cached content.
This API enables web applications to read and write files on the local file system with user permission, blurring the line between web and native applications. Users must explicitly grant access through file pickers. Use cases include code editors, image editors, document processors, and backup tools. Currently Chrome and Edge support this API fully, with limited Firefox and Safari support. The API maintains security by requiring explicit user interaction for file access.
The Fetch API provides a modern, promise-based interface for making HTTP requests, replacing the older XMLHttpRequest. It offers cleaner syntax, better error handling, streaming responses, CORS support, and integration with other modern APIs. Fetch works with async/await for readable asynchronous code and supports request/response interception with Service Workers. All modern browsers support Fetch, making it the standard for network requests.
WebSocket enables full-duplex communication between browsers and servers over a single TCP connection, allowing servers to push data to clients instantly. Unlike HTTP polling, WebSocket maintains persistent connections with minimal overhead. Use cases include chat applications, real-time notifications, live sports scores, collaborative editing, and multiplayer games. WebSocket requires server-side support and works best over HTTPS (WSS protocol).
Server-Sent Events (SSE) enable servers to push updates to browsers over HTTP, simpler than WebSocket but unidirectional. SSE automatically reconnects if connections drop, uses standard HTTP, and works through most proxies and firewalls. It's ideal for real-time feeds like news updates, stock tickers, notification streams, and progress monitoring. SSE is simpler than WebSocket when bidirectional communication isn't needed.
This API provides information about network connection type and quality, enabling adaptive experiences based on connectivity. Applications can detect 2G/3G/4G/5G/WiFi connections, estimate bandwidth, and adjust behavior accordingly. Use cases include reducing video quality on slow connections, deferring large downloads, preloading on WiFi, and showing offline indicators. Support varies by browser, with Chrome and Edge offering the most complete implementation.
The Geolocation API provides access to device location through GPS, WiFi, or cellular triangulation. It requires explicit user permission and works best on mobile devices with GPS. Use cases include maps and navigation, local search results, location-based services, and check-in features. The API provides latitude, longitude, accuracy, altitude, and heading. Always handle permission denial gracefully and explain why location access is needed.
These APIs access device accelerometer and gyroscope data, enabling motion-based interactions. Device Orientation provides compass heading and device tilt, while Device Motion gives acceleration data. Use cases include motion controls in games, step counters, shake-to-undo gestures, and augmented reality. Safari requires user permission for motion data due to privacy concerns around fingerprinting. These APIs work best on mobile devices with built-in sensors.
The Vibration API enables triggering device vibration through JavaScript, enhancing mobile user experience with haptic feedback. It works only on devices with vibration motors (primarily smartphones). Use cases include notification feedback, game effects, button press confirmation, and accessibility features. The API allows single vibrations or patterns. Support is primarily on Android; iOS Safari doesn't support this API.
This API provides information about device battery level and charging status, enabling power-aware applications. Apps can reduce functionality on low battery, defer intensive operations until charging, or show battery warnings. However, browser support is declining due to privacy concerns around battery status fingerprinting. Chrome and Firefox previously supported this but removed it; limited implementations remain.
The Web Crypto API provides cryptographic operations in browsers, enabling encryption, decryption, signing, verification, and hashing without third-party libraries. It uses native implementations for better performance and security. Use cases include end-to-end encryption, secure password hashing, digital signatures, and certificate management. All modern browsers support Web Crypto in secure contexts (HTTPS). The API supports algorithms like AES, RSA, ECDSA, and SHA.
This API enables programmatic access to password managers and federated login systems, simplifying sign-in experiences. It supports password credentials, federated credentials (Google, Facebook login), and public key credentials (WebAuthn). The API enables auto-sign-in, credential storage, and seamless authentication. Chrome and Edge have strong support; Firefox and Safari support varies. Combined with WebAuthn, it enables passwordless authentication.
The Payment Request API standardizes checkout experiences, enabling browsers to handle payment details securely. It reduces cart abandonment by simplifying forms, stores payment methods securely, supports multiple payment methods, and works with digital wallets like Apple Pay and Google Pay. The API improves mobile checkout significantly. Support is good in Chrome, Edge, and Safari; limited in Firefox.
This API enables querying permission status for various browser features without triggering permission prompts. Developers can check if permissions are granted, denied, or require prompting, enabling better UX by explaining features before requesting access. It works with geolocation, notifications, camera, microphone, and other permissions. Implementation varies across browsers, with Chrome offering the most complete support.
Service Workers are programmable network proxies that intercept network requests, enabling offline functionality, background sync, and push notifications. They power progressive web apps, cache resources for offline use, enable app-like experiences, and reduce server load. Service Workers run on separate threads, don't block the UI, and persist across page loads. They require HTTPS and careful cache management to avoid serving stale content.
Web Workers enable running JavaScript on background threads, preventing UI freezing during intensive computations. They're perfect for data processing, image manipulation, complex calculations, and parsing large files. Workers communicate with the main thread via messages. They can't access the DOM but can use many APIs. Shared Workers enable communication between multiple tabs. All modern browsers support Web Workers.
The Performance API provides precise timing information and performance metrics, essential for optimization. It measures page load times, resource loading, user timing marks, and long tasks. Navigation Timing shows page load phases, Resource Timing tracks individual resource loads, and User Timing enables custom performance marks. This data helps identify bottlenecks and optimize user experience.
Intersection Observer efficiently detects when elements enter or exit the viewport, replacing expensive scroll event handlers. Use cases include lazy loading images, infinite scrolling, visibility analytics, and animation triggers. It performs better than scroll listeners by not blocking the main thread and can observe multiple elements efficiently. All modern browsers support Intersection Observer.
Promises represent asynchronous operations, providing cleaner alternatives to callback hell. Async/await syntax makes asynchronous code look synchronous, improving readability dramatically. These features are fundamental to modern JavaScript, used with Fetch, IndexedDB, and countless APIs. All modern browsers support Promises and async/await; transpilation handles older browsers.
JavaScript modules enable organizing code into reusable pieces with explicit imports and exports. They provide better dependency management, enable tree shaking for smaller bundles, and avoid global namespace pollution. Modern browsers support ES6 modules natively with script type="module". Module support enables using npm packages directly in browsers without build steps, though bundlers remain common for optimization.
WebAssembly (Wasm) is a binary instruction format enabling near-native performance in browsers. It allows running code written in C, C++, Rust, and other languages in browsers at speeds approaching native applications. Use cases include games, video editing, image processing, CAD software, and scientific computing. WebAssembly works alongside JavaScript, not replacing it. All modern browsers support WebAssembly.
Proxies enable intercepting and customizing operations on objects, creating powerful metaprogramming capabilities. They power reactive frameworks like Vue 3, enable validation, logging, and computed properties. Reflect provides methods for interceptable JavaScript operations. Together they enable creating sophisticated abstractions and frameworks. Modern browsers support Proxies, though performance can be slower than direct property access.
Feature detection tests whether specific APIs exist rather than assuming browser capabilities based on user agent strings. This approach is more reliable because user agents can be spoofed, browser features vary by version, and some browsers partially implement features. Feature detection enables progressive enhancement where advanced features enhance experiences for capable browsers while maintaining basic functionality everywhere.
Always detect features by testing for their existence: check if APIs are defined, test if functions return expected results, and handle both presence and absence gracefully. Use try-catch blocks for APIs that might throw errors. Libraries like Modernizr automate detection for many features. Never assume feature support based on browser name or version alone.
Build experiences that work everywhere, then layer enhanced functionality for capable browsers. Start with core HTML and basic JavaScript, add modern features conditionally, and always provide fallbacks. This ensures universal access while delivering optimal experiences to modern browsers. Test with features disabled to ensure basic functionality remains intact.
Polyfills provide implementations of modern features for older browsers, while transpilers convert modern syntax to older equivalents. Babel transpiles ES6+ to ES5, while polyfills add missing APIs. Use feature detection to load polyfills conditionally, reducing bundle size for modern browsers. Consider the maintenance burden of supporting very old browsers versus encouraging users to update.
Different browsers implement features at different paces and sometimes with varying behaviors. Chrome and Edge (both Chromium-based) share implementations, Firefox uses Gecko with its own timeline, and Safari often lags but protects user privacy more aggressively. Test in all major browsers during development, not just after completion.
Historically, browsers used vendor prefixes (-webkit-, -moz-, -ms-, -o-) for experimental features. Modern browsers avoid prefixes, instead using feature flags for experimental APIs. When using CSS or JavaScript features, check whether prefixes are still needed. Autoprefixer automatically adds necessary CSS prefixes based on browser support targets.
Mobile browsers have unique constraints and capabilities. iOS Safari differs significantly from desktop Safari, Android Chrome has device-specific variations, and mobile browsers have different performance characteristics. Test on actual devices when possible, not just in desktop browser developer tools. Mobile testing reveals touch interaction issues, performance problems, and viewport quirks.
Feature support depends on browser version, implementation priorities, and platform capabilities. Older browsers lack modern features, some browsers prioritize certain APIs over others, and platform limitations affect availability. Update your browser to the latest version for maximum feature support. Some features require specific hardware (like WebXR needing VR headsets).
If this tool shows many unsupported features, especially fundamental ones like Fetch API or Promises, you should update immediately. Outdated browsers have security vulnerabilities, missing modern features, and compatibility issues. Most browsers auto-update, but check manually in settings. Using current browser versions ensures security, performance, and compatibility.
Polyfills can add missing APIs to older browsers, though with performance costs. However, some features like WebGL or WebRTC require browser engine support and can't be polyfilled. For missing features, provide fallback experiences or encourage users to update browsers. Consider whether supporting very old browsers is worth development time.
Browsers implement features at different rates based on priorities, resources, and philosophies. Chrome and Edge often lead in new features, Firefox balances innovation with stability, and Safari prioritizes privacy sometimes at the cost of feature velocity. These differences reflect browser vendors' strategies and user base needs.
Experimental features lack stable specifications and might change or be removed. Use them for exploration and prototypes, but avoid in production unless providing robust fallbacks. Check feature stability through resources like MDN Web Docs and Can I Use. Once features stabilize across browsers, they become safe for production use.
Test during initial development to establish baseline compatibility, before major deployments to catch regressions, and periodically as browsers update and new features become available. Automated testing with tools like Selenium or Playwright helps maintain cross-browser compatibility. Manual testing on real devices catches issues automated tests might miss.