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# Safari Technology Preview 220 Release Notes

Learn about the latest web technology updates in Safari Technology Preview: CSS, DOM, JavaScript, Media, Rendering, Web Animations, Web API, Web Inspector, and WebRTC.

## Overview

[Safari Technology Preview](https://webkit.org/blog/6017/introducing-safari-technology-preview/) Release 220 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: [294488@main…295070@main](https://github.com/WebKit/WebKit/compare/341926ba0aa90ad33296fe9464df5ba3823efc25...984de83064446098ffd0ed2a896b8e0a48cffed5)

### CSS

#### New Features

- Added support for `field-sizing` to override the default sizing behavior of form elements and adjust size to fit their contents. ([295370@main](https://commits.webkit.org/295370@main))  (151949208)

#### Resolved Issues

- Fixed grid sizing with inline-size containment and auto-fit columns is incorrectly sized. ([295023@main](https://commits.webkit.org/295023@main))  (108897961)
- Fixed a bug where an anchor-positioned element does not properly render when it’s initially hidden from view, then shown. ([294924@main](https://commits.webkit.org/294924@main))  (148608785)

### DOM

#### Resolved Issues

- Fixed the serialization of `CDATASection` nodes in HTML. ([294547@main](https://commits.webkit.org/294547@main))  (150739105)

### JavaScript

#### New Features

- Added support for `@@dispose` and `@@asyncDispose` from the Explicit Resource Management Proposal behind runtime flag. ([294592@main](https://commits.webkit.org/294592@main))  (150816114)
- Added support for `SuppressedError` from the Explicit Resource Management Proposal behind runtime flag. ([294774@main](https://commits.webkit.org/294774@main))  (151132111)
- Added support for `DisposableStack` constructor from the Explicit Resource Management Proposal behind runtime flag. ([294880@main](https://commits.webkit.org/294880@main))  (151280591)

### Media

#### Resolved Issues

- Fixed MediaSession to handle SVG icons with subresources. ([294499@main](https://commits.webkit.org/294499@main))  (150665852)
- Fixed `MediaCapabilitiesDecodingInfo.configuration` to be correctly populated even when `.supported` is `false`. ([294957@main](https://commits.webkit.org/294957@main))  (150680756)

### Rendering

#### Resolved Issues

- Fixed invisible `<audio>` controls when transformed due to incorrect coordinate space calculations for clipped child elements. ([294694@main](https://commits.webkit.org/294694@main))  (150526971)
- Fixed centering text for `<input type=button>` elements with `display: flex`. ([294785@main](https://commits.webkit.org/294785@main))  (151148821)
- Fixed showing a resize cursor even when text overlaps the resize control. ([294907@main](https://commits.webkit.org/294907@main))  (151309503)

### Web Animations

#### Resolved Issues

- Fixed CSS scroll-driven animations on pages using `requestAnimationFrame` to animate correctly after navigating away and back to the page. ([294889@main](https://commits.webkit.org/294889@main))  (141528296)

### Web API

#### Resolved Issues

- Fixed making the SpeechRecognition interface available only within a secure context. ([294887@main](https://commits.webkit.org/294887@main))  (151240414)

### Web Inspector

#### Resolved Issues

- Fixed parsing sourcemaps asynchronously so that large sourcemaps do not block rendering. ([294875@main](https://commits.webkit.org/294875@main))  (151269154)

### WebRTC

#### Resolved Issues

- Fixed the `configurationchange` event to fire when a microphone’s audio unit changes its echo cancellation mode, ensuring web pages are notified of such changes to update track settings accordingly. ([294839@main](https://commits.webkit.org/294839@main))  (150770940)

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