Release Notes for Safari Technology Preview 217

Apr 16, 2025

by Jon Davis

Safari Technology Preview Release 217 is now available for download for macOS Sequoia 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: 292535@main…293326@main

CSS

Resolved Issues

  • Fixed @scope to create a style nested context. (292821@main) (148101373)
  • Fixed changing content-visibility from visible to hidden to repaint correctly. (292960@main) (148273903)
  • Fixed color to not be a high-priority property. (293082@main) (148361501)

Forms

Resolved Issues

  • Fixed setValidity of ElementInternals to handle missing optional anchor parameter. (292770@main) (123744294)

JavaScript

Resolved Issues

  • Fixed performance of Math.hypot() that was significantly slower than Math.sqrt(). (292549@main) (141821484)
  • Fixed Array#indexOf and Array#includes to treat +0 and -0 as the same value. (293134@main) (148472519)

Media

Resolved Issues

  • Fixed subtitle tracks with no srclang to be shown with the correct label. (292577@main) (147722563)

Rendering

Resolved Issues

  • Fixed the text indicator sometimes getting clipped during a bounce animation. (292612@main) (147602900)
  • Fixed geometry values inside content-visibility: hidden subtrees. (293267@main) (148553259)
  • Fixed not marking content-visibility: hidden content for layout when targeting content-visibility: auto. (293304@main) (148663896)

SVG

Resolved Issues

  • Fixed: Improved handling of SVG images with subresources. (293259@main) (148607855)

Tables

Resolved Issues

  • Fixed table layout to only be triggered when inline-size is not auto. (292536@main) (147636653)

Web API

New Features

  • Added support for scrollMargin in IntersectionObserver. (293306@main) (117527880)
  • Added support for the alg parameter when importing or exporting Edward’s-curve based JSON Web Keys in WebCrypto. (293089@main) (147323269)

Web Extensions

Resolved Issues

  • Fixed "excludeMatches" array in scripting.registerContentScripts() API getting ignored in Safari web extensions. (293106@main) (145489255) (FB16590857)

Web Inspector

New Features

  • Added support for exporting and importing data from worker targets in the Timelines tab. (292991@main) (145330533)
  • Added a a badge for <slot> to quickly jump to the assigned node in the Elements tab. (292966@main) (148297936)

Resolved Issues

  • Fixed a performance issue when blackboxing a large number of sourcemaps. (292997@main) (148116377)

WebRTC

New Features

  • Added support for exposing CSRC information for RTCEncodedVideoStream. (293088@main) (76548862)
  • Added serialisation of RTCEncodedAudioFrame and RTCEncodedVideoFrame. (293185@main) (148244334)
  • Added support for ImageCapture.grabFrame. (293243@main) (148425176)

Resolved Issues

  • Fixed enumerateDevices returning devices as available when permissions are denied. (292921@main) (147313922)
  • Fixed getUserMedia not using the correct camera or microphone if devices change while user is answering the permission prompt. (292696@main) (147762070)
  • FixedenumerateDevices to not check for device permission. (293003@main) (148094614)
  • Fixed WebRTC encoded transform to transfer to the RTC encoded frame array buffer. (293232@main) (148343876)
  • Fixed RTC encoded frame timestamp should be persistent. (293238@main) (148580865)