Release Notes for Safari Technology Preview 239

Mar 12, 2026

by Jon Davis

Safari Technology Preview Release 239 is now available for download 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: 307619@main…308417@main.

Accessibility

Resolved Issues

  • Fixed an issue where SVG <use> elements referencing <symbol> elements inside an <img> were incorrectly included as unnamed images in VoiceOver’s Images web rotor. (308126@main) (98999595)
  • Fixed an issue where VoiceOver was unable to access aria-owned rows and their cells in grids and tables. (308087@main) (168770938)
  • Fixed an issue where VoiceOver could not find focusable splitter elements when navigating to the next or previous form control. (308089@main) (170187464)
  • Fixed an issue where controls with aria-labelledby did not use the native label’s geometry when both the control and its ARIA label had no visible bounding box. (307727@main) (170518900)

CSS

New Features

  • Added support for the :open pseudo-class for <input> elements. (308148@main) (170804152)

Resolved Issues

  • Fixed an issue where tables with collapsed borders incorrectly calculated the first row width, causing excess border width to spill into the table’s margin area. (308311@main) (149675907)
  • Fixed an issue where inset box-shadow was incorrectly positioned on table cells with collapsed borders. (307661@main) (169254286)
  • Fixed an issue where display: grid subgrids inside grid-lanes containers incorrectly contributed their item intrinsic sizes to the parent’s track sizing algorithm. (308253@main) (170168798)
  • Fixed the baseline calculation for inline-block elements so that when overflow is not visible, the baseline is correctly set to the bottom margin edge. (307718@main) (170575015)
  • Fixed an issue where replaced elements did not correctly apply min-height and min-width constraints in certain configurations. (308212@main) (170765025)
  • Fixed an issue where children with percentage heights inside absolutely positioned elements using intrinsic height values (fit-content, min-content, max-content) incorrectly resolved against the containing block’s height instead of being treated as auto. (308226@main) (171179193)

Editing

Resolved Issues

  • Fixed an issue where execCommand('FormatBlock') did not preserve inline styles of replaced block elements, causing text formatting to be lost when pasting content. (308365@main) (157657531)
  • Fixed an issue where text-indent flickered or was ignored on contenteditable elements while typing. (307646@main) (170280101)

Forms

Resolved Issues

  • Fixed an issue where a readonly date <input> could still be edited via keyboard using the date picker. (307934@main) (169488939)

MathML

Resolved Issues

  • Fixed an issue where dynamic changes to <mo> element attributes did not trigger a relayout. (308014@main) (170907029)
  • Fixed positioning of the <mprescripts> element within <mmultiscripts> layout. (308013@main) (170909975)
  • Fixed an issue where the MathML fraction bar was not painted when its thickness was equal to its width. (308025@main) (170934351)
  • Fixed an issue where <none> and <mprescripts> elements were not laid out as <mrow> elements in MathML. (308050@main) (170940035)

Media

Resolved Issues

  • Fixed an issue where the VideoFrame constructor did not handle the video color range correctly for NV12 (I420 BT601) video frames. (307649@main) (170299037)

PDF

Resolved Issues

  • Fixed a regression where form fields in PDF documents were not readable when editing in dark mode. (308330@main) (171198060)

Rendering

Resolved Issues

  • Fixed an issue where images were incorrectly stretched in certain page layouts. (307751@main) (170270187)

Scrolling

Resolved Issues

  • Fixed an issue where interrupting scroll momentum caused the scrolling container to stop rendering and hit-testing to be misplaced. (308215@main) (116205365)
  • Fixed an issue where pages could become blank and jump to the top after dynamically loading new content when scroll anchoring was enabled. (308352@main) (170889205)
  • Fixed an issue where scroll anchoring could cause pages to scroll to negative offsets. (308320@main) (171221075)

Web API

Resolved Issues

  • Fixed an issue where the change event was not fired on <input> and <textarea> elements when they lost focus while another application was in the foreground. (308203@main) (98526540)
  • Fixed an issue where the dragend event had incorrect coordinates when dragging within a nested <iframe>. (308216@main) (170750013)

Web Inspector

New Features

  • Added color contrast information within the Color Picker in Web Inspector. (308318@main) (113887185)

Resolved Issues

  • Fixed an issue in the Network panel where the Request / Response menu did not remember the user’s previously selected value. (308142@main) (108231795)
  • Fixed an issue in the Elements tab where “Copy HTML” only copied HTML for a single node when multiple nodes are selected. (307826@main) (169196441)

WebAssembly

Resolved Issues

  • Fixed WebAssembly streaming compilation APIs to accept the optional compileOptions parameter required to enable JS String builtins. (308419@main) (170989896)

WebRTC

Resolved Issues

  • Fixed an issue where RTCPeerConnection.addIceCandidate() did not reject when the connection was already closed. (307702@main) (170470988)