# Safari Technology Preview 181 Release Notes Learn about the latest web technology updates in Safari Technology Preview: CSS, HTML, JavaScript, Media, Rendering, and SVG. ## Overview [Safari Technology Preview](https://webkit.org/blog/6017/introducing-safari-technology-preview/) Release 181 is now [available for download](https://developer.apple.com/safari/resources/) for macOS Sonoma and macOS Ventura. If you already have Safari Technology Preview installed, you can update it in System Settings under General → Software Update. This release includes WebKit changes between: [268060@main…269057@main](https://github.com/WebKit/WebKit/compare/6c5b713260df52cc170be32034565f28e1022dc2...cf6d4e0d9fc41d5bc300fe9c01f7c18d30030e3a). ### Accessibility #### Resolved Issues - Fixed non-group and non-tree-item children of `role="treeitem"` elements becoming stale after dynamic changes. ([268385@main](https://commits.webkit.org/268385@main)) (115936550) ### CSS #### New Features - Added support for `content-visibility`. ([268313@main](https://commits.webkit.org/268313@main)) (114734606) #### Resolved Issues - Fixed `` to never serialize to a single value. ([268291@main](https://commits.webkit.org/268291@main)) (111750372) - Fixed computation of the `from-font` value for `font-size-adjust`. ([269041@main](https://commits.webkit.org/269041@main)) (113328110) - Fixed `` to forbid generic families. ([268203@main](https://commits.webkit.org/268203@main)) (113746537) - Fixed nested subgrids from contributing to the calculation of the enclosing track size. ([268947@main](https://commits.webkit.org/268947@main)) (114271839) - Fixed offset path inset shapes with a `border-radius`. ([268192@main](https://commits.webkit.org/268192@main)) (115316728) - Fixed blend modes with Interoperability improvements. ([268173@main](https://commits.webkit.org/268173@main)) (115688282) - Fixed not serializing `at ` in `circle()` or `ellipse()` if unspecified. ([268344@main](https://commits.webkit.org/268344@main)) (115866108) - Fixed serialization of `shape-outside`. ([268365@main](https://commits.webkit.org/268365@main)) (115938310) - Fixed serialization issues with `clip-path` and `offset-path`. ([268379@main](https://commits.webkit.org/268379@main)) (115953688) - Fixed `circle()` and `ellipse()` to use non-offset starting position for CSS Motion Path. ([268400@main](https://commits.webkit.org/268400@main)) (115962433) - Fixed non-orthogonal subgrid margin, border, and padding to be considered for self-align baseline items in the same alignment context. ([268804@main](https://commits.webkit.org/268804@main)) (116206243) ### DOM #### Resolved Issues - Fixed handling tasks scheduled for web pages in the back-forward cache. ([268782@main](https://commits.webkit.org/268782@main)) (116349535) ### Forms #### Resolved Issues - Fixed serialization of `autocomplete` with a `webauthn` token. ([268520@main](https://commits.webkit.org/268520@main)) (116107937) ### HTML #### New Features - Added support for `one-time-code` as an allowed `autocomplete` field name. ([268097@main](https://commits.webkit.org/268097@main)) (115684196) #### Resolved Issues - Fixed respecting the first parseable `` value. ([268064@main](https://commits.webkit.org/268064@main)) (64705222) - Fixed `[dir=auto]` invalidation with password fields. ([268322@main](https://commits.webkit.org/268322@main)) (115887776) ### JavaScript #### New Features - Implemented Annex B block-level function hoisting for global scope. ([268553@main](https://commits.webkit.org/268553@main)) (53234438) - Added support for `Promise.withResolvers`. ([268892@main](https://commits.webkit.org/268892@main)) (116473362) #### Resolved Issues - Fixed stringification algorithm of the Function constructor to match specifications. ([268633@main](https://commits.webkit.org/268633@main)) (102065151) - Fixed generator functions to not be Annex B hoisting candidates. ([268352@main](https://commits.webkit.org/268352@main)) (114213642) - Fixed the algorithm determining Annex B hoisted functions to perform lexical scope chain walk. ([268302@main](https://commits.webkit.org/268302@main)) (115504046) - Fixed block-level function declarations to not allow shadow `var` bindings. ([268634@main](https://commits.webkit.org/268634@main)) (116202546) - Fixed duplicate lexical bindings to only be allowed for function declarations. ([268671@main](https://commits.webkit.org/268671@main)) (116252189) ### Loading #### Resolved Issues - Fixed Link-stylesheet elements to not fire load events for non-text/css and non-2XX responses. ([268535@main](https://commits.webkit.org/268535@main)) (116112223) - Fixed link-stylesheet elements to not fire load events for non-2XX responses such as 3XX responses that do not redirect. ([268779@main](https://commits.webkit.org/268779@main)) (116331826) ### Media #### New Features - Added support for variable packet durations in Vorbis streams. ([268625@main](https://commits.webkit.org/268625@main)) (99712672) - Added MediaStream support for `whiteBalanceMode`. ([268102@main](https://commits.webkit.org/268102@main)) (115552800) ### Rendering #### Resolved Issues - Fixed uses of `backdrop-filter: blur()` with `mix-blend-mode` to render properly. ([268426@main](https://commits.webkit.org/268426@main)) (34470317) - Fixed resizing behavior with `writing-mode: vertical-rl` or `direction: rtl`. ([268157@main](https://commits.webkit.org/268157@main)) (102620110) - Fixed handling iframes with `display: none`. (112494003) - Fixed opacity and rendering the root element background image. ([268156@main](https://commits.webkit.org/268156@main)) (115396444) - Fixed the color of the drop shadow to preserve its alpha channel. ([268233@main](https://commits.webkit.org/268233@main)) (115812347) - Fixed filters with outsets to repaint the entire filterRegion if GraphicsStyles are used. ([268282@main](https://commits.webkit.org/268282@main)) (115817290) - Fixed compositing the filter style transparency layers to not clip the destination context. ([268341@main](https://commits.webkit.org/268341@main)) (115901634) #### Deprecations - Removed `margin-trim` behavior for floats to match specification changes. ([268227@main](https://commits.webkit.org/268227@main)) (115794102) ### SVG #### Resolved Issues - Fixed the SVG mask to work as a mask-resource for the CSS `mask-image`. ([268272@main](https://commits.webkit.org/268272@main)) (114465545) ### Web API #### New Features - Added support for CSS Custom Highlights API. ([268673@main](https://commits.webkit.org/268673@main)) (116255516) #### Resolved Issues - Fixed `formAssociated=true` causing a custom element to become focusable. ([268756@main](https://commits.webkit.org/268756@main)) (115909679) - Fixed TextTrackCue constructor to match updated specifications. ([268644@main](https://commits.webkit.org/268644@main)) (116002871) ### Web Inspector #### Resolved Issues - Fixed resource sorting in the Sources tab to consider the filename and extensions separately. ([268557@main](https://commits.webkit.org/268557@main)) (72905353) ### WebDriver #### Resolved Issues - Fixed dispatched mouse events always having `buttons` property set to zero. ([268529@main](https://commits.webkit.org/268529@main)) (116049187) ### WebGL #### Resolved Issues - Fixed a bug where multi-level textures would lose levels in WebGL. ([268819@main](https://commits.webkit.org/268819@main)) (116362216) ### WebRTC #### Resolved Issues - Fixed media tracks obtained with `{"width":1920,"height":1080,"frameRate":24}`. ([268386@main](https://commits.webkit.org/268386@main)) (61747755) - Fixed video quality when using TransformStream with Simulcast. ([268912@main](https://commits.webkit.org/268912@main)) (110395571) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)