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

HTML5

  1. accept attribute for file input
  2. Add to home screen (A2HS)
  3. async attribute for external scripts
  4. Attributes for form submission
  5. Audio element
  6. Audio Tracks
  7. Autofocus attribute
  8. Canvas (basic support)
  9. Canvas blend modes
  10. classList (DOMTokenList)
  11. Color input type
  12. contenteditable attribute (basic support)
  13. Custom Elements (V1)
  14. Custom protocol handling
  15. Datalist element
  16. dataset & data-* attributes
  17. Date and time input types
  18. defer attribute for external scripts
  19. Details & Summary elements
  20. Dialog element
  21. disabled attribute of the fieldset element
  22. Download attribute
  23. Drag and Drop
  24. Email, telephone & URL input types
  25. Form attribute
  26. Form validation
  27. getElementsByClassName
  28. Hashchange event
  29. hidden attribute
  30. HTML Imports
  31. HTML Media Capture
  32. HTML templates
  33. HTML5 semantic elements
  34. indeterminate checkbox
  35. Inline SVG in HTML5
  36. input event
  37. input placeholder attribute
  38. inputmode attribute
  39. Lazy loading via attribute for images & iframes
  40. Link type "noreferrer"
  41. maxlength attribute for input and textarea elements
  42. meter element
  43. Minimum length attribute for input fields
  44. Multiple file selection
  45. naturalWidth & naturalHeight image properties
  46. Number input type
  47. OffscreenCanvas
  48. PageTransitionEvent
  49. Path2D
  50. Pattern attribute for input fields
  51. Picture element
  52. Ping attribute
  53. PNG favicons
  54. Printing Events
  55. progress element
  56. Range input type
  57. readonly attribute of input and textarea elements
  58. rel=noopener
  59. relList (DOMTokenList)
  60. Reversed attribute of ordered lists
  61. Ruby annotation
  62. sandbox attribute for iframes
  63. Search input type
  64. Selection controls for input & textarea
  65. Session history management
  66. Spellcheck attribute
  67. srcdoc attribute for iframes
  68. Srcset and sizes attributes
  69. Subresource Integrity
  70. SVG favicons
  71. tabindex global attribute
  72. Text API for Canvas
  73. Video element
  74. Video Tracks
  75. wbr (word break opportunity) element
  76. WebGL - 3D Canvas graphics
  77. WebGL 2.0
  78. Context menu item (menuitem element)
  79. Custom Elements (deprecated V0 spec)
  80. Offline web applications
  81. Portals
  82. seamless attribute for iframes
  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. document.elementFromPoint()
  16. document.head
  17. document.scrollingElement
  18. DOM manipulation convenience methods
  19. DOMContentLoaded
  20. DOMMatrix
  21. Dynamic Adaptive Streaming over HTTP (MPEG-DASH)
  22. Element.closest()
  23. Element.insertAdjacentElement() & Element.insertAdjacentText()
  24. EventTarget.addEventListener()
  25. EventTarget.dispatchEvent
  26. FLAC audio format
  27. focusin & focusout events
  28. HEIF/ISO Base Media File Format
  29. HEVC/H.265 video format
  30. HTMLElement.innerText
  31. HTTP/2 protocol
  32. HTTP/3 protocol
  33. JPEG 2000 image format
  34. JPEG XL image format
  35. JPEG XR image format
  36. KeyboardEvent.code
  37. KeyboardEvent.getModifierState()
  38. KeyboardEvent.key
  39. KeyboardEvent.location
  40. MathML
  41. Media Fragments
  42. MP3 audio format
  43. MPEG-4/H.264 video format
  44. Mutation events
  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. WebM video format
  67. WebP image format
  68. WebVTT - Web Video Text Tracks
  69. WOFF - Web Open Font Format
  70. WOFF 2.0 - Web Open Font Format
  71. XHTML served as application/xhtml+xml
  72. Declarative Shadow DOM
  73. Document Policy
  74. EOT - Embedded OpenType fonts
  75. HTTP Live Streaming (HLS)
  76. KeyboardEvent.charCode
  77. KeyboardEvent.which
  78. Resource Hints: Lazyload
  79. Shadow DOM (deprecated V0 spec)
  80. SPDY protocol
  81. URL Scroll-To-Text Fragment
  82. XHTML+SMIL animation
  83. 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. Full Screen API
  35. Gamepad API
  36. Geolocation
  37. getUserMedia/Stream API
  38. Gyroscope
  39. High Resolution Time API
  40. ImageCapture API
  41. IndexedDB
  42. IndexedDB 2.0
  43. IntersectionObserver
  44. Magnetometer
  45. matches() DOM method
  46. matchMedia
  47. Media Capture from DOM Elements API
  48. Media Source Extensions
  49. MediaRecorder API
  50. Mutation Observer
  51. Navigation Timing API
  52. navigator.hardwareConcurrency
  53. Object RTC (ORTC) API for WebRTC
  54. Online/offline status
  55. Orientation Sensor
  56. Page Visibility
  57. Payment Request API
  58. Permissions API
  59. Permissions Policy
  60. Picture-in-Picture
  61. Pointer events
  62. Pointer Lock API
  63. Proximity API
  64. Push API
  65. requestAnimationFrame
  66. requestIdleCallback
  67. Resize Observer
  68. Resource Timing
  69. Screen Orientation
  70. Screen Wake Lock API
  71. Scroll methods on elements (scroll, scrollTo, scrollBy)
  72. scrollIntoView
  73. Selection API
  74. Server Timing
  75. Server-sent events
  76. Service Workers
  77. Shared Web Workers
  78. Streams
  79. Synchronous Clipboard API
  80. TextEncoder & TextDecoder
  81. Touch events
  82. URL API
  83. URLSearchParams
  84. User Timing API
  85. Vibration API
  86. Web Animations API
  87. Web Audio API
  88. Web Cryptography
  89. Web MIDI API
  90. Web Notifications
  91. Web Share API
  92. Web Sockets
  93. Web Storage - name/value pairs
  94. Web Workers
  95. WebCodecs API
  96. WebGPU
  97. WebRTC Peer-to-peer connections
  98. WebTransport
  99. WebXR Device API
  100. XMLHttpRequest advanced features
  101. Background Sync API
  102. Cookie Store API
  103. Directory selection from file input
  104. Do Not Track API
  105. document.evaluate & XPath
  106. Document.execCommand()
  107. Efficient Script Yielding: setImmediate()
  108. Element.scrollIntoViewIfNeeded()
  109. Feature Policy
  110. FIDO U2F API
  111. File System Access API
  112. Filesystem & FileWriter API
  113. Input Method Editor API
  114. IntersectionObserver V2
  115. Network Information API
  116. Speech Recognition API
  117. Speech Synthesis API
  118. Trusted Types for DOM manipulation
  119. Web Bluetooth
  120. Web NFC
  121. Web Serial API
  122. Web SQL Database
  123. WebHID API
  124. WebUSB
  125. WebVR API
  126. All JS API features