compat.spec.whatwg.orgCompatibility Standard

Compatibility Living Standard — Last Updated 24 January 2024 Participate: GitHub whatwg/compat ( new issue , open issues ) Chat on Matrix Commits: GitHub whatwg/compat/commits Snapshot as of this commit @compatstandard Tests: web-platform-tests compat/ ( ongoing work ) Translations (non-normative) : 日本語 Abstract This standard describes a collection of web platform features that web browsers need to support for compatibility with the de facto web. Table of Contents 1 Introduction 2 Conformance 3 CSS Compatibility 3.1 CSS At-rules 3.2 CSS Media Queries 3.2.1 -webkit-device-pixel-ratio 3.2.2 -webkit-transform-3d 3.3 CSS Gradient Functions 3.3.1 -webkit-linear-gradient() 3.3.2 -webkit-radial-gradient() 3.3.3 -webkit-repeating-linear-gradient() 3.3.4 -webkit-repeating-radial-gradient() 3.4 CSS Properties 3.4.1 Legacy name aliases 3.4.2 Prefixed legacy name aliases 3.4.3 Non-aliased vendor prefixed properties 3.4.4 Property mappings 3.4.5 Keyword mappings 3.4.6 Text Fill and Stroking 3.4.6.1 Foreground Text Color: the -webkit-text-fill-color property 3.4.6.2 Text Stroke Color: the -webkit-text-stroke-color property 3.4.6.3 Text Stroke Thickness: the -webkit-text-stroke-width property 3.4.6.4 Text Stroke Shorthand: the -webkit-text-stroke property 3.5 CSS Property values 3.5.1 Additional touch-action values 4 DOM Compatibility 4.1 The WebKitCSSMatrix interface 4.2 window.orientation API 4.2.1 window.orientation angle 4.2.2 Event Handlers on Window objects and body elements 5 The User-Agent String 5.1 User-Agent Tokens 5.1.1 User-Agent Token Reference 5.2 Meta Structure 5.3 Chrome 5.3.1 Chrome User-Agent pattern 5.3.2 Chrome-specific tokens 5.4 Firefox 5.4.1 Firefox User-Agent pattern 5.4.2 Firefox-specific tokens 5.5 Safari 5.5.1 Safari User-Agent pattern 5.5.2 Safari-specific tokens Acknowledgements Intellectual property rights Index Terms defined by this specification Terms defined by reference References Normative References Informative References Property Index @media Descriptors IDL Index 1. Introduction This section is non-normative. There exists an increasingly large corpus of web content that depends on web browsers supporting a number of specific vendor CSS properties and DOM APIs for functionality or layout. This holds especially true for mobile-optimized web content, which is highly dependent on -webkit- -prefixed properties. This specification aims to describe the minimal set of -webkit- -prefixed CSS properties and DOM APIs that user agents are required to support for web compatibility, which aren’t specified elsewhere. The HTTP User-Agent header field as found in major browsers today is also described. 2. Conformance All diagrams, examples, and notes in this specification are non-normative, as are all sections explicitly marked non-normative. Everything else in this specification is normative. The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119. For readability, these words do not appear in all uppercase letters in this specification. [RFC2119] Requirements phrased in the imperative as part of algorithms (such as "strip any leading space characters" or "return false and terminate these steps") are to be interpreted with the meaning of the keyword ("must", "should", "may", etc.) used in introducing the algorithm. Conformance requirements phrased as algorithms or specific steps may be implemented in any manner, so long as the end result is equivalent. (In particular, the algorithms defined in this specification are intended to be easy to follow, and not intended to be performant.) 3. CSS Compatibility 3.1. CSS At-rules The following -webkit- vendor prefixed at-rules must be supported as aliases of the corresponding unprefixed at-rules : -webkit- prefixed at-rule alias unprefixed at-rule @-webkit-keyframes @keyframes 3.2. CSS Media Queries 3.2.1. -webkit-device-pixel-ratio Name: -webkit-device-pixel-ratio For: @media Value: number Type: range -webkit-device-pixel-ratio must be treated as an alias of the resolution range type media feature , with its value interpreted as a dppx unit. The min- or max- prefixes on range features must not apply to -webkit-device-pixel-ratio , instead the following aliases must be used: legacy -webkit- prefixed range media feature alias standard prefixed range media feature -webkit-min-device-pixel-ratio min-resolution -webkit-max-device-pixel-ratio max-resolution 3.2.2. -webkit-transform-3d Name: -webkit-transform-3d For: @media Value: mq-boolean Type: discrete The -webkit-transform-3d media feature is used to query whether the user agent supports CSS 3D transforms. [css-transforms-1] If the user agent supports 3D transforms, the value will be 1. Otherwise the value is 0. 3.3. CSS Gradient Functions 3.3.1. -webkit-linear-gradient() The -webkit-linear-gradient() gradient function must be treated as an alias of linear-gradient as defined in [css3-images-20110217] . 3.3.2. -webkit-radial-gradient() The -webkit-radial-gradient() gradient function must be treated as an alias of radial-gradient as defined in [css3-images-20110217] . 3.3.3. -webkit-repeating-linear-gradient() The -webkit-repeating-linear-gradient() gradient function must be treated as an alias of repeating-linear-gradient as defined in [css3-images-20110217] . 3.3.4. -webkit-repeating-radial-gradient() The -webkit-repeating-radial-gradient() gradient function must be treated as an alias of repeating-radial-gradient as defined in [css3-images-20110217] . 3.4. CSS Properties 3.4.1. Legacy name aliases The following -webkit- vendor prefixed properties must be supported as legacy name aliases of the corresponding unprefixed property: -webkit- prefixed property alias unprefixed property -webkit-align-items align-items -webkit-align-content align-content -webkit-align-self align-self -webkit-animation-name animation-name -webkit-animation-duration animation-duration -webkit-animation-timing-function animation-timing-function -webkit-animation-iteration-count animation-iteration-count -webkit-animation-direction animation-direction -webkit-animation-play-state animation-play-state -webkit-animation-delay animation-delay -webkit-animation-fill-mode animation-fill-mode -webkit-animation animation -webkit-backface-visibility backface-visibility -webkit-background-clip background-clip -webkit-background-origin background-origin -webkit-background-size Not really a legacy name alias . See issue #28 . background-size -webkit-border-bottom-left-radius border-bottom-left-radius -webkit-border-bottom-right-radius border-bottom-right-radius -webkit-border-top-left-radius border-top-left-radius -webkit-border-top-right-radius border-top-right-radius -webkit-border-radius border-radius -webkit-box-shadow box-shadow -webkit-box-sizing box-sizing -webkit-flex flex -webkit-flex-basis flex-basis -webkit-flex-direction flex-direction -webkit-flex-flow flex-flow -webkit-flex-grow flex-grow -webkit-flex-shrink flex-shrink -webkit-flex-wrap flex-wrap -webkit-filter filter -webkit-justify-content justify-content -webkit-mask mask -webkit-mask-box-image mask-border -webkit-mask-box-image-outset mask-border-outset -webkit-mask-box-image-repeat mask-border-repeat -webkit-mask-box-image-slice mask-border-slice -webkit-mask-box-image-source mask-border-source -webkit-mask-box-image-width mask-border-width -webkit-mask-clip mask-clip -webkit-mask-composite mask-composite -webkit-mask-image mask-image -webkit-mask-origin mask-origin -webkit-mask-position mask-position -webkit-mask-repeat mask-repeat -webkit-mask-size mask-size -webkit-order order -webkit-perspective perspective -webkit-perspective-origin perspective-origin -webkit-transform-origin transform-origin -webkit-transform-style transform-style -webkit-transform transform -webkit-transition-delay transition-delay -webkit-transition-duration transition-duration...