Can I use
?

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 Relative colors
  94. CSS Repeating Gradients
  95. CSS resize property
  96. CSS revert value
  97. CSS Scroll Snap
  98. CSS Scroll-behavior
  99. CSS Shapes Level 1
  100. CSS Subgrid
  101. CSS Table display
  102. CSS text-box-trim & text-box-edge
  103. CSS text-indent
  104. CSS text-justify
  105. CSS text-orientation
  106. CSS text-wrap: balance
  107. CSS touch-action property
  108. CSS unset value
  109. CSS user-select: none
  110. CSS Variables (Custom Properties)
  111. CSS widows & orphans
  112. CSS will-change property
  113. CSS writing-mode property
  114. CSS3 2D Transforms
  115. CSS3 3D Transforms
  116. CSS3 Background-image options
  117. CSS3 Border images
  118. CSS3 Border-radius (rounded corners)
  119. CSS3 Box-shadow
  120. CSS3 Box-sizing
  121. CSS3 Colors
  122. CSS3 Cursors (original values)
  123. CSS3 Cursors: zoom-in & zoom-out
  124. CSS3 font-kerning
  125. CSS3 image-orientation
  126. CSS3 Media Queries
  127. CSS3 Multiple backgrounds
  128. CSS3 Multiple column layout
  129. CSS3 object-fit/object-position
  130. CSS3 Opacity
  131. CSS3 Overflow-wrap
  132. CSS3 selectors
  133. CSS3 tab-size
  134. CSS3 text-align-last
  135. CSS3 Text-overflow
  136. CSS3 Text-shadow
  137. CSS3 Transitions
  138. CSS3 word-break
  139. display: flow-root
  140. display: run-in
  141. Font unicode-range subsetting
  142. Full Screen API
  143. gap property for Flexbox
  144. getComputedStyle
  145. Intrinsic & Extrinsic Sizing
  146. LCH and Lab color values
  147. letter-spacing CSS property
  148. Media Queries: interaction media features
  149. Media Queries: Range Syntax
  150. Media Queries: resolution feature
  151. Pointer events
  152. prefers-color-scheme media query
  153. prefers-reduced-motion media query
  154. Rebeccapurple color
  155. rem (root em) units
  156. selector list argument of :not()
  157. selector list argument of :nth-child and :nth-last-child CSS pseudo-classes
  158. Small, Large, and Dynamic viewport units
  159. SVG in CSS backgrounds
  160. system-ui value for font-family
  161. text-decoration styling
  162. text-emphasis styling
  163. TTF/OTF - TrueType and OpenType font support
  164. ui-serif, ui-sans-serif, ui-monospace and ui-rounded values for font-family
  165. Variable fonts
  166. View Transitions API (single-document)
  167. Viewport units: vw, vh, vmin, vmax
  168. Window.devicePixelRatio
  169. :focus-within CSS pseudo-class
  170. Background-clip: text
  171. background-position-x & background-position-y
  172. CSS -webkit-user-drag property
  173. CSS @scroll-timeline
  174. CSS Backdrop Filter
  175. CSS Canvas Drawings
  176. CSS Environment Variables env()
  177. CSS font-smooth
  178. CSS overflow: overlay
  179. CSS pointer-events (for HTML)
  180. CSS Reflections
  181. CSS scrollbar styling
  182. CSS text-size-adjust
  183. CSS text-stroke and text-fill
  184. CSS zoom
  185. CSS3 attr() function for all properties
  186. Explicit descendant combinator >>
  187. High-quality kerning pairs & ligatures
  188. Scoped CSS
  189. Scoped Styles: the @scope rule
  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. 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/HEIC image 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. zstd (Zstandard) content-encoding
  73. Declarative Shadow DOM
  74. Document Policy
  75. EOT - Embedded OpenType fonts
  76. HTTP Live Streaming (HLS)
  77. KeyboardEvent.charCode
  78. KeyboardEvent.which
  79. Resource Hints: Lazyload
  80. Shadow DOM (deprecated V0 spec)
  81. SPDY protocol
  82. URL Scroll-To-Text Fragment
  83. XHTML+SMIL animation
  84. 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
  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