---
title: Safari Technology Preview 185 Release Notes
framework: safari-technology-preview-release-notes
role: article
role_heading: Article
path: safari-technology-preview-release-notes/stp-release-185
---
# Safari Technology Preview 185 Release Notes
Learn about the latest web technology updates in Safari Technology Preview: Accessibility, CSS, HTML, Media, Rendering, Web API, Web Inspector, WebAuthn, and WebGPU.
## Overview
Overview Safari Technology Preview Release 185 is now available for download 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: 271111@main…271831@main. Accessibility Resolved Issues Fixed: Removed the default ARIA-level heading for a heading role, matching removal from ARIA specifications. (271497@main) (119059172) CSS New Features Added support for align-content on block containers. (271818@main) (114740670) Added percentage values support for letter-spacing and word-spacing. (271357@main) (116562262) Added support for scroll anchoring with overflow-anchor. (271790@main) (118365809) Added support for @scope. (271670@main) (119261250) Added support for ::grammar-error and ::spelling-error (271684@main) (119314048) Resolved Issues Fixed CSS counters to update properly on style changes. (271451@main) (109416780) Fixed: Updated Full Size Kana table to Unicode 15. (271276@main) (111508663) Fixed missing user-agent stylesheet rules for MathML fractions. (271337@main) (116922348) Fixed selection gaps to get painted with the expected ::selection pseudo-element color. (271129@main) (117796745) Fixed ::backdrop to be allowed after ::slotted(). (271366@main) (119015204) Fixed: Removed support for special first track handling to align with the evolving Masonry standard. (271757@main) (119041053) HTML New Features Added support for . (271736@main) (119378678) Media New Features Added WebCodecs VP9 profile 2 support. (271238@main) (118879753) Resolved Issues Fixed an HEVC decoder issue when translating annexb data. (271728@main) (116768196) Fixed AV1-in-MP4 codec string not shown in Show Media Stats. (271187@main) (118850797) Fixed getDisplayMedia frameRate always at 30 regardless of constraints. (271233@main) (118874132) Fixed to not loop if current time or duration is zero. (271256@main) (118902468) Fixed in-band captions wrapping unnecessarily. (271415@main) (119024855) Rendering Resolved Issues Fixed: Removed the text-decorationcolor override quirk. (271338@main) (102920597) Fixed shadow invalidation issue in vertical-rl mode. (271416@main) (111915460) Fixed text in flex items not breaking under specific conditions. (271122@main) (118796634) Web API New Features Added Element.prototype.setHTMLUnsafe(), ShadowRoot.prototype.setHTMLUnsafe(), and Document.parseHTMLUnsafe() methods. (271423@main) (115345128) Resolved Issues Fixed updating resizeBy and resizeTo to use int rather than float to align with specifications. (271194@main) (118872048) Fixed the CookieChangeEvent to not be exposed when the Cookie Store API is disabled. (271243@main) (118902989) Fixed