# Safari Technology Preview 199 Release Notes Learn about the latest web technology updates in Safari Technology Preview: Apple Pay, CSS, Editing, JavaScript, Media, Rendering, Text, and WebRTC. ## Overview [Safari Technology Preview](https://webkit.org/blog/6017/introducing-safari-technology-preview/) Release 199 is now [available for download](https://developer.apple.com/safari/resources/) for macOS Sequoia beta and macOS Sonoma. 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: [280287@main…280674@main](https://github.com/WebKit/WebKit/compare/d161b493908aac112d8682eb7eab88760b1bd130...0032df775eaa08a9a58a5b7814b2b79dc35a688f). ### Apple Pay #### Resolved Issues - Fixed arbitrary 8 digit limit on a line item’s total amount. ([280584@main](https://commits.webkit.org/280584@main)) (112078798) ### CSS #### New Features - Added support for `(prefers-contrast: custom)`. ([280383@main](https://commits.webkit.org/280383@main)) (103658875) #### Resolved Issues - Fixed computed values for `text-box-edge`. ([280413@main](https://commits.webkit.org/280413@main)) (117643064) - Fixed: Improved large Grid performance. ([280473@main](https://commits.webkit.org/280473@main)) (130728344) ### Editing #### Resolved Issues - Fixed an issue where input method editing would sporadically drop the composition range. ([280291@main](https://commits.webkit.org/280291@main)) (130020224) ### JavaScript #### New Features - Added support for `Uint8Array.prototype.toBase64` and `Uint8Array.prototype.toHex`. ([280654@main](https://commits.webkit.org/280654@main)) (129045737) #### Resolved Issues - Fixed `Intl.DurationFormat` for `numeric` and `2-digit`. ([280460@main](https://commits.webkit.org/280460@main)) (130279541) ### Media #### Resolved Issues - Fixed missing picture-in-picture when leaving Safari with picture-in-picture enabled from video viewer. ([279877@main](https://commits.webkit.org/279877@main)) (124376686) - Fixed a hang in WebAudio. ([280604@main](https://commits.webkit.org/280604@main)) (130531570) ### Rendering #### Resolved Issues - Fixed support for border, padding, and margin on `mfrac` and `mspace` elements in MathML. ([280665@main](https://commits.webkit.org/280665@main)) (131119823) ### Text #### Resolved Issues - Fixed disclosure counter styles to consider `writing-mode`. ([280433@main](https://commits.webkit.org/280433@main)) (130468537) ### WebRTC #### Resolved Issues - Fixed `RTCAudioPlayoutStats` to match web specifications. ([280461@main](https://commits.webkit.org/280461@main)) (130767124) --- 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)