<!--
{
  "documentType" : "article",
  "framework" : "Safari Technology Preview Release Notes",
  "identifier" : "/documentation/Safari-Technology-Preview-Release-Notes/stp-release-207",
  "metadataVersion" : "0.1.0",
  "role" : "article",
  "title" : "Safari Technology Preview 207 Release Notes"
}
-->

# Safari Technology Preview 207 Release Notes

Learn about the latest web technology updates in Safari Technology Preview: CSS, Forms, JavaScript, Loading, Networking, Rendering, Scrolling, Web Extensions, and Web Inspector.

## Overview

[Safari Technology Preview](https://webkit.org/blog/6017/introducing-safari-technology-preview/) Release 207 is now [available for download](https://developer.apple.com/safari/resources/) 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: [284744@main…285486@main](https://github.com/WebKit/WebKit/compare/28b90713af7c0d5887a894cc63d2e5f32541cf29...8a011645e7ae8104a27f7a3401668084311e7e63).

### CSS

#### Resolved Issues

- Fixed: Updated the `shape()` function to match the proposed syntax. ([285442@main](https://commits.webkit.org/285442@main))  (138126105)

### Forms

#### New Features

- Added enhancements to `<input type=color>` to support `alpha` and `colorspace` attributes. ([285448@main](https://commits.webkit.org/285448@main))  (137737348)

### JavaScript

#### New Features

- Added support for `Atomics.pause`. ([284917@main](https://commits.webkit.org/284917@main))  (137571229)

#### Resolved Issues

- Fixed: Stopped using resolved scope as `this` value when calling functions. ([284931@main](https://commits.webkit.org/284931@main))  (77915872)
- Fixed `Set.prototype` methods to invoke `keys()` without arguments. ([284747@main](https://commits.webkit.org/284747@main))  (137395979)
- Fixed `Array.from()`, `Array.fromAsync()`, and `TypedArray.from()` to invoke `document.all` passed as a mapper. ([284868@main](https://commits.webkit.org/284868@main))  (137490201)
- Fixed `Intl.DurationFormat` to have a value limit to match the specification. ([285131@main](https://commits.webkit.org/285131@main))  (137885273)
- Fixed a rounding error for `Intl.DurationFormat`. ([285482@main](https://commits.webkit.org/285482@main))  (138261569)

### Loading

#### New Features

- Added `noopener-allow-popups` support in Cross-Origin-Opener-Policy. ([284866@main](https://commits.webkit.org/284866@main))  (129664445)

### Networking

#### New Features

- Added Brotli support for Compression Streams. ([285391@main](https://commits.webkit.org/285391@main))  (99159497)

### Rendering

#### Resolved Issues

- Fixed `scriptlevel` multipler for font-size in MathML. ([285069@main](https://commits.webkit.org/285069@main))  (137671252)
- Fixed a flex container with no flex item to not run flex layout. ([285129@main](https://commits.webkit.org/285129@main))  (137884128)

### Scrolling

#### Resolved Issues

- Fixed changes to the “scrolling” attribute on an iframe element already in the DOM to take effect. ([284947@main](https://commits.webkit.org/284947@main))  (98911472)

### Web Extensions

#### New Features

- Added support for `documentId` to the `sender` message object. ([284855@main](https://commits.webkit.org/284855@main))  (137532821)
- Added support for `documentId` to `tabs.sendMessage()` and `tabs.connect()`. ([285438@main](https://commits.webkit.org/285438@main))  (137532897)

#### Resolved Issues

- Fixed `tabs.executeScript` ignoring the `frameId` parameter. ([284915@main](https://commits.webkit.org/284915@main))  (137449521) (FB15420092)

### Web Inspector

#### Resolved Issues

- Fixed: Changed the label to use “Disable site-specific quirks” in settings. ([285136@main](https://commits.webkit.org/285136@main))  (137779118)

---

Copyright &copy; 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)