# Safari Technology Preview 221 Release Notes Learn about the latest web technology updates in Safari Technology Preview: Accessibility, Forms, JavaScript, Media, PDF, Rendering, Web API, Web Inspector, and WebRTC. ## Overview [Safari Technology Preview](https://webkit.org/blog/6017/introducing-safari-technology-preview/) Release 221 is now [available for download](https://developer.apple.com/safari/resources/) for macOS Tahoe and macOS Sequoia. 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: [295071@main…295660@main](https://github.com/WebKit/WebKit/compare/8446b16946ec50ae6e35ca6b6acc98bd29f33568...243f58ea8132097c921e7bbf19aa783f02a12b65) ### Accessibility #### Resolved Issues - Fixed `aria-expanded` attribute support on navigation links. ([295356@main](https://commits.webkit.org/295356@main)) (141163086) ### Forms #### Resolved Issues - Fixed updating scrollbar appearance correctly for the page and `` elements. ([295590@main](https://commits.webkit.org/295590@main)) (151496190) - Fixed programmatically assigned File objects to display the correct filename in `<input>` elements, even without a file path. ([295458@main](https://commits.webkit.org/295458@main)) (152048377) ### JavaScript #### Resolved Issues - Fixed nested negated classes resulting in incorrect matches. ([295277@main](https://commits.webkit.org/295277@main)) (151000852) ### Media #### Resolved Issues - Fixed MP4 seeking with b-frames to prevent out-of-order frame display by suppressing frames with earlier presentation timestamps following the seek point. ([295304@main](https://commits.webkit.org/295304@main)) (140415210) ### PDF #### Resolved Issues - Fixed “Open with Preview” button to open a PDF in the Preview app. ([295475@main](https://commits.webkit.org/295475@main)) (148680145) ### Rendering #### Resolved Issues - Fixed an issue causing a `<canvas>` element to disappear for one frame if a view transition occurs. ([295467@main](https://commits.webkit.org/295467@main)) (149709642) ### Web API #### Resolved Issues - Fixed escaping `<` and `>` when serializing HTML attribute values. ([295149@main](https://commits.webkit.org/295149@main)) (150520333) ### Web Inspector #### New Features - Added support for recording Workers in the Timelines tab. ([295485@main](https://commits.webkit.org/295485@main)) (151721737) #### Resolved Issues - Fixed pretty-printing CSS to avoid adding a space after the universal selector (`*`) when followed by a pseudo-class or pseudo-element, preventing unintended changes to CSS selector behavior. ([295447@main](https://commits.webkit.org/295447@main)) (71544976) (FB8906066) ### WebRTC #### New Features - Added support for exposing a default system speaker device. ([295206@main](https://commits.webkit.org/295206@main)) (151761469) --- 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)