The Web platform: Browser technologies

Core platform
HTML
DOM
ECMAScript and JavaScript
URL
Fetch and CORS
XMLHttpRequest
Encoding
CSS features
CSS roadmap
Animations
Background-image options
Border images
Border radius (rounded corners)
Box shadows
Box sizing
Downloadable fonts (@font-face)
Fixed positioning (position:fixed)
Font-feature settings
Gradients
Hyphenation
Media Queries
Multiple-column layout
Multiple backgrounds
Opacity
Pointer events
Selectors (level 3)
Text overflow
Text shadows
Transforms (2D)
Transforms (3D)
Transitions
Graphics and typography
Canvas
WebGL
SVG
WOFF
MathML
Media
Web Audio API
WebVTT
Media Source Extensions
Media Fragments
Platform interaction, events, messaging
Web Notifications
Cross-document messaging
Channel messaging
Fullscreen
Geolocation
Device Orientation
DOM Events
Pointer Events
Touch Events
Pointer Lock
Gamepad
getUserMedia
Battery Status
Vibration
Beacon
HTML Media Capture (the capture attribute)
Clipboard API and events
Storage and Files
Web Storage
Indexed Database
File API
Blob URLs
File Reader
Real-time communication
WebRTC
Object RTC (ORTC) API for WebRTC
WebSocket protocol
WebSocket API
Server-Sent Events
Web Components
Explainer
Custom Elements
Shadow DOM
HTML Imports
Templates
HTML bonus features
classList (DOMTokenList)
dataset (data-* attributes)
async for scripts
defer for scripts
Session-history management
hashchange
Sandboxed iframe
Drag and drop
contentEditable
HTML Editing APIs
UndoManager and DOM Transaction
ARIA
Performance optimization and analysis
Web Workers
Shared Workers
Timing control for script-based animations
Navigation Timing
Page Visibility
User Timing
Performance Timeline
High Resolution Time
Security and privacy
Content Security Policy
Crypto
Tracking Preference Expression (DNT)
Other core-platform bonus features
Structured clones
Transferable objects
Mutation observers
Streams
DOM Parsing and Serialization
DOM XPath
Quirks Mode
Promises
JSON parsing
Typed Array
Service Workers
Selectors API
matches(selector) method
matchMedia(media_query_list) method
data URLs
Foundations
HTTP
TLS
Cookies
Origin
Unicode
MIME Sniffing
Various other
WebIDL
Link header
Content-Disposition header
A feature history of the modern Web Platform

Legend

 
 
When can I use...
 
 
MDN (Mozilla Developer Network Reference)
 
 
Tests: associated test suite
 
 
HTML5 Please recommends as ready to use
 
 
HTML5 Please recommends using with caution