Can I use
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Index

CSS

  1. #rrggbbaa hex color notation
  2. ::first-letter CSS pseudo-element selector
  3. ::placeholder CSS pseudo-element
  4. ::selection CSS pseudo-element
  5. :default CSS pseudo-class
  6. :dir() CSS pseudo-class
  7. :focus-visible CSS pseudo-class
  8. :has() CSS relational pseudo-class
  9. :in-range and :out-of-range CSS pseudo-classes
  10. :indeterminate CSS pseudo-class
  11. :is() CSS pseudo-class
  12. :optional CSS pseudo-class
  13. :placeholder-shown CSS pseudo-class
  14. @font-face Web fonts
  15. Blending of HTML/SVG elements
  16. calc() as CSS unit value
  17. Case-insensitive CSS attribute selectors
  18. ch (character) unit
  19. Crisp edges/pixelated images
  20. CSS 2.1 selectors
  21. CSS ::marker pseudo-element
  22. CSS :any-link selector
  23. CSS :read-only and :read-write selectors
  24. CSS @when / @else conditional rules
  25. CSS all property
  26. CSS Anchor Positioning
  27. CSS Animation
  28. CSS Appearance
  29. CSS background-attachment
  30. CSS background-blend-mode
  31. CSS background-position edge offsets
  32. CSS background-repeat round and space
  33. CSS box-decoration-break
  34. CSS caret-color
  35. CSS Cascade Layers
  36. CSS clip-path property (for HTML)
  37. CSS color() function
  38. CSS Conical Gradients
  39. CSS Container Queries (Size)
  40. CSS Container Query Units
  41. CSS Container Style Queries
  42. CSS Containment
  43. CSS content-visibility
  44. CSS Counter Styles
  45. CSS Counters
  46. CSS Cross-Fade Function
  47. CSS currentColor value
  48. CSS Device Adaptation
  49. CSS display: contents
  50. CSS element() function
  51. CSS Exclusions Level 1
  52. CSS Feature Queries
  53. CSS Filter Effects
  54. CSS filter() function
  55. CSS first-line pseudo-element
  56. CSS Flexible Box Layout Module
  57. CSS Font Loading
  58. CSS font-display
  59. CSS font-feature-settings
  60. CSS font-palette
  61. CSS font-size-adjust
  62. CSS font-stretch
  63. CSS font-variant-alternates
  64. CSS font-variant-numeric
  65. CSS Generated content for pseudo-elements
  66. CSS grab & grabbing cursors
  67. CSS Gradients
  68. CSS Grid Layout (level 1)
  69. CSS hanging-punctuation
  70. CSS Hyphenation
  71. CSS image-set
  72. CSS Initial Letter
  73. CSS initial value
  74. CSS inline-block
  75. CSS justify-content: space-evenly
  76. CSS line-clamp
  77. CSS Logical Properties
  78. CSS Masks
  79. CSS math functions min(), max() and clamp()
  80. CSS min/max-width/height
  81. CSS Motion Path
  82. CSS namespaces
  83. CSS Nesting
  84. CSS outline properties
  85. CSS overflow property
  86. CSS overflow-anchor (Scroll Anchoring)
  87. CSS overscroll-behavior
  88. CSS page-break properties
  89. CSS Painting API
  90. CSS position:fixed
  91. CSS position:sticky
  92. CSS print-color-adjust
  93. CSS Regions
  94. CSS Relative color syntax
  95. CSS Repeating Gradients
  96. CSS resize property
  97. CSS revert value
  98. CSS Scroll Snap
  99. CSS Scroll-behavior
  100. CSS scrollbar styling
  101. CSS Shapes Level 1
  102. CSS Subgrid
  103. CSS Table display
  104. CSS text-box-trim & text-box-edge
  105. CSS text-indent
  106. CSS text-justify
  107. CSS text-orientation
  108. CSS text-wrap: balance
  109. CSS touch-action property
  110. CSS unset value
  111. CSS user-select: none
  112. CSS Variables (Custom Properties)
  113. CSS widows & orphans
  114. CSS will-change property
  115. CSS writing-mode property
  116. CSS zoom
  117. CSS3 2D Transforms
  118. CSS3 3D Transforms
  119. CSS3 Background-image options
  120. CSS3 Border images
  121. CSS3 Border-radius (rounded corners)
  122. CSS3 Box-shadow
  123. CSS3 Box-sizing
  124. CSS3 Colors
  125. CSS3 Cursors (original values)
  126. CSS3 Cursors: zoom-in & zoom-out
  127. CSS3 font-kerning
  128. CSS3 image-orientation
  129. CSS3 Media Queries
  130. CSS3 Multiple backgrounds
  131. CSS3 Multiple column layout
  132. CSS3 object-fit/object-position
  133. CSS3 Opacity
  134. CSS3 Overflow-wrap
  135. CSS3 selectors
  136. CSS3 tab-size
  137. CSS3 text-align-last
  138. CSS3 Text-overflow
  139. CSS3 Text-shadow
  140. CSS3 Transitions
  141. CSS3 word-break
  142. display: flow-root
  143. display: run-in
  144. Font unicode-range subsetting
  145. Fullscreen API
  146. gap property for Flexbox
  147. getComputedStyle
  148. Intrinsic & Extrinsic Sizing
  149. LCH and Lab color values
  150. letter-spacing CSS property
  151. Media Queries: interaction media features
  152. Media Queries: Range Syntax
  153. Media Queries: resolution feature
  154. Pointer events
  155. prefers-color-scheme media query
  156. prefers-reduced-motion media query
  157. Rebeccapurple color
  158. rem (root em) units
  159. Scoped Styles: the @scope rule
  160. selector list argument of :not()
  161. selector list argument of :nth-child and :nth-last-child CSS pseudo-classes
  162. Small, Large, and Dynamic viewport units
  163. SVG in CSS backgrounds
  164. system-ui value for font-family
  165. text-decoration styling
  166. text-emphasis styling
  167. TTF/OTF - TrueType and OpenType font support
  168. ui-serif, ui-sans-serif, ui-monospace and ui-rounded values for font-family
  169. Variable fonts
  170. View Transitions API (single-document)
  171. Viewport units: vw, vh, vmin, vmax
  172. Window.devicePixelRatio
  173. :focus-within CSS pseudo-class
  174. Background-clip: text
  175. background-position-x & background-position-y
  176. CSS -webkit-user-drag property
  177. CSS Backdrop Filter
  178. CSS Canvas Drawings
  179. CSS Environment Variables env()
  180. CSS font-smooth
  181. CSS overflow: overlay
  182. CSS pointer-events (for HTML)
  183. CSS Reflections
  184. CSS text-size-adjust
  185. CSS text-stroke and text-fill
  186. CSS3 attr() function for all properties
  187. Explicit descendant combinator >>
  188. High-quality kerning pairs & ligatures
  189. Scoped attribute
  190. All CSS features

HTML5

  1. accept attribute for file input
  2. async attribute for external scripts
  3. Attributes for form submission
  4. Audio element
  5. Audio Tracks
  6. Autofocus attribute
  7. Canvas (basic support)
  8. Canvas blend modes
  9. classList (DOMTokenList)
  10. Color input type
  11. contenteditable attribute (basic support)
  12. Custom Elements (V1)
  13. Custom protocol handling
  14. Datalist element
  15. dataset & data-* attributes
  16. Date and time input types
  17. defer attribute for external scripts
  18. Details & Summary elements
  19. Dialog element
  20. disabled attribute of the fieldset element
  21. Download attribute
  22. Drag and Drop
  23. Email, telephone & URL input types
  24. Form attribute
  25. Form validation
  26. getElementsByClassName
  27. Hashchange event
  28. hidden attribute
  29. HTML Imports
  30. HTML Media Capture
  31. HTML templates
  32. HTML5 semantic elements
  33. indeterminate checkbox
  34. Inline SVG in HTML5
  35. input event
  36. input placeholder attribute
  37. inputmode attribute
  38. Lazy loading via attribute for images & iframes
  39. Link type "noreferrer"
  40. maxlength attribute for input and textarea elements
  41. meter element
  42. Minimum length attribute for input fields
  43. Multiple file selection
  44. naturalWidth & naturalHeight image properties
  45. Number input type
  46. OffscreenCanvas
  47. PageTransitionEvent
  48. Path2D
  49. Pattern attribute for input fields
  50. Picture element
  51. Ping attribute
  52. PNG favicons
  53. Printing Events
  54. progress element
  55. Range input type
  56. readonly attribute of input and textarea elements
  57. rel=noopener
  58. relList (DOMTokenList)
  59. Reversed attribute of ordered lists
  60. Ruby annotation
  61. sandbox attribute for iframes
  62. Search input type
  63. Selection controls for input & textarea
  64. Session history management
  65. Spellcheck attribute
  66. srcdoc attribute for iframes
  67. Srcset and sizes attributes
  68. Subresource Integrity
  69. SVG favicons
  70. tabindex global attribute
  71. Text API for Canvas
  72. Video element
  73. Video Tracks
  74. wbr (word break opportunity) element
  75. WebGL - 3D Canvas graphics
  76. WebGL 2.0
  77. Context menu item (menuitem element)
  78. Custom Elements (deprecated V0 spec)
  79. Offline web applications
  80. Portals
  81. seamless attribute for iframes
  82. Selectlist - Customizable select element
  83. All HTML5 features

Other

  1. "once" event listener option
  2. AAC audio file format
  3. Animated PNG (APNG)
  4. autocomplete attribute: on & off values
  5. AV1 video format
  6. AVIF image format
  7. Brotli Accept-Encoding/Content-Encoding
  8. Built-in PDF viewer
  9. ChildNode.remove()
  10. Client Hints: DPR, Width, Viewport-Width
  11. COLR/CPAL(v0) Font Formats
  12. COLR/CPAL(v1) Font Formats
  13. CSS Paged Media (@page)
  14. Data URIs
  15. Declarative Shadow DOM
  16. document.elementFromPoint()
  17. document.head
  18. document.scrollingElement
  19. DOM manipulation convenience methods
  20. DOMContentLoaded
  21. DOMMatrix
  22. Dynamic Adaptive Streaming over HTTP (MPEG-DASH)
  23. Element.closest()
  24. Element.insertAdjacentElement() & Element.insertAdjacentText()
  25. EventTarget.addEventListener()
  26. EventTarget.dispatchEvent
  27. FLAC audio format
  28. focusin & focusout events
  29. HEIF/HEIC image format
  30. HEVC/H.265 video format
  31. HTMLElement.innerText
  32. HTTP/2 protocol
  33. HTTP/3 protocol
  34. JPEG 2000 image format
  35. JPEG XL image format
  36. JPEG XR image format
  37. KeyboardEvent.code
  38. KeyboardEvent.getModifierState()
  39. KeyboardEvent.key
  40. KeyboardEvent.location
  41. MathML
  42. Media Fragments
  43. MP3 audio format
  44. MPEG-4/H.264 video format
  45. Node.compareDocumentPosition()
  46. Node.textContent
  47. Ogg Vorbis audio format
  48. Ogg/Theora video format
  49. Opus audio format
  50. Passive event listeners
  51. PNG alpha transparency
  52. querySelector/querySelectorAll
  53. Resource Hints: dns-prefetch
  54. Resource Hints: modulepreload
  55. Resource Hints: preconnect
  56. Resource Hints: prefetch
  57. Resource Hints: preload
  58. Resource Hints: prerender
  59. SDCH Accept-Encoding/Content-Encoding
  60. Shadow DOM (V1)
  61. Signed HTTP Exchanges (SXG)
  62. theme-color Meta Tag
  63. WAI-ARIA Accessibility features
  64. Wav audio format
  65. WebAssembly
  66. WebAssembly BigInt to i64 conversion in JS API
  67. WebAssembly Bulk Memory Operations
  68. WebAssembly Import/Export of Mutable Globals
  69. WebAssembly Multi-Value
  70. WebAssembly Non-trapping float-to-int Conversion
  71. WebAssembly Reference Types
  72. WebAssembly Sign Extension Operators
  73. WebAssembly SIMD
  74. WebAssembly Threads and Atomics
  75. WebM video format
  76. WebP image format
  77. WebVTT - Web Video Text Tracks
  78. WOFF - Web Open Font Format
  79. WOFF 2.0 - Web Open Font Format
  80. XHTML served as application/xhtml+xml
  81. zstd (Zstandard) content-encoding
  82. Document Policy
  83. EOT - Embedded OpenType fonts
  84. HTTP Live Streaming (HLS)
  85. KeyboardEvent.charCode
  86. KeyboardEvent.which
  87. Mutation events
  88. Resource Hints: Lazyload
  89. Shadow DOM (deprecated V0 spec)
  90. SPDY protocol
  91. URL Scroll-To-Text Fragment
  92. XHTML+SMIL animation
  93. All Other features

JS API

  1. AbortController & AbortSignal
  2. Accelerometer
  3. Ambient Light Sensor
  4. Asynchronous Clipboard API
  5. Auxclick
  6. Base64 encoding and decoding
  7. Basic console logging functions
  8. Battery Status API
  9. Beacon API
  10. Blob constructing
  11. Blob URLs
  12. BroadcastChannel
  13. Channel messaging
  14. console.time and console.timeEnd
  15. Constraint Validation API
  16. createImageBitmap
  17. Credential Management API
  18. Cross-document messaging
  19. Cross-Origin Resource Sharing
  20. crypto.getRandomValues()
  21. CSS.supports() API
  22. CustomEvent
  23. DeviceOrientation & DeviceMotion events
  24. Document Object Model Range
  25. document.currentScript
  26. DOM Parsing and Serialization
  27. Element.getBoundingClientRect()
  28. Element.insertAdjacentHTML()
  29. Encrypted Media Extensions
  30. Fetch
  31. File API
  32. FileReader API
  33. FileReaderSync
  34. Gamepad API
  35. Geolocation
  36. getUserMedia/Stream API
  37. Gyroscope
  38. High Resolution Time API
  39. ImageCapture API
  40. IndexedDB
  41. IndexedDB 2.0
  42. IntersectionObserver
  43. Magnetometer
  44. matches() DOM method
  45. matchMedia
  46. Media Capture from DOM Elements API
  47. Media Source Extensions
  48. MediaRecorder API
  49. Mutation Observer
  50. Navigation Timing API
  51. navigator.hardwareConcurrency
  52. Object RTC (ORTC) API for WebRTC
  53. Online/offline status
  54. Orientation Sensor
  55. Page Visibility
  56. Passkeys
  57. Payment Request API
  58. Permissions API
  59. Permissions Policy
  60. Picture-in-Picture
  61. Pointer Lock API
  62. Proximity API
  63. Push API
  64. requestAnimationFrame
  65. requestIdleCallback
  66. Resize Observer
  67. Resource Timing (basic support)
  68. Screen Orientation
  69. Screen Wake Lock API
  70. Scroll methods on elements (scroll, scrollTo, scrollBy)
  71. scrollIntoView
  72. Selection API
  73. Server Timing
  74. Server-sent events
  75. Service Workers
  76. Shared Web Workers
  77. Streams
  78. Synchronous Clipboard API
  79. TextEncoder & TextDecoder
  80. Touch events
  81. URL API
  82. URLSearchParams
  83. User Timing API
  84. Vibration API
  85. Web Animations API
  86. Web Audio API
  87. Web Cryptography
  88. Web MIDI API
  89. Web Notifications
  90. Web Share API
  91. Web Sockets
  92. Web Storage - name/value pairs
  93. Web Workers
  94. WebCodecs API
  95. WebGPU
  96. WebRTC Peer-to-peer connections
  97. WebTransport
  98. WebXR Device API
  99. XMLHttpRequest advanced features
  100. Background Sync API
  101. Cookie Store API
  102. Directory selection from file input
  103. Do Not Track API
  104. document.evaluate & XPath
  105. Document.execCommand()
  106. Efficient Script Yielding: setImmediate()
  107. Element.scrollIntoViewIfNeeded()
  108. Feature Policy
  109. FIDO U2F API
  110. File System Access API
  111. Filesystem & FileWriter API
  112. Input Method Editor API
  113. IntersectionObserver V2
  114. Network Information API
  115. Speech Recognition API
  116. Speech Synthesis API
  117. Trusted Types for DOM manipulation
  118. Web Bluetooth
  119. Web NFC
  120. Web Serial API
  121. Web SQL Database
  122. WebHID API
  123. WebUSB
  124. WebVR API
  125. All JS API features