New WebKit Features in Safari 15.6

Safari 15.6 is the seventh major release of Safari since last fall’s Safari 15.0.

Continuing efforts from Safari 15.5, WebKit’s work for this version of Safari was focused predominately on fixing bugs and polishing existing features. Safari 15.6 does include one new feature for web developers — the :modal CSS pseudo-class.

Safari 15.6 is available for macOS Monterey 12.5, macOS Big Sur, macOS Catalina, iPadOS 15.6, and iOS 15.6. You can update to Safari 15.6 on macOS Big Sur and macOS Catalina by going to System Preferences → Software Update → More info, and choosing to update Safari.

Developer Features

Newly defined in CSS Selectors level 4, the :modal pseudo-class can be used to select dialog elements opened with the showModal() API.

Fixes and Polish

And now, the list of bug fixes.


  • Fixed object-fit causing iframe contents to shift
  • Fixed inert behavior to apply to ::after, ::before, and ::marker pseudo-elements
  • Fixed :focus-visible matching a mouse click after a second element.focus() call
  • Fixed logical inline and logical block viewport units to be based on the current element’s writing-mode


  • Fixed resetting writing direction when inserting a new paragraph breaks out of a quoted reply block
  • Fixed managed pasteboard on iOS to work for all managed locations including managed Safari domains


  • Fixed page layout automatically when new fonts are installed


  • Fixed <link rel=preconnect> to respect crossorigin=anonymous and prevent sending credentials to different-origin links


  • Fixed blank video playback with only audio
  • Fixed replaceTrack with different constraints preventing sending packets
  • Fixed WebAudio playback rate speeding up for a few seconds when using createMediaElementSource
  • Fixed stalled playback when seeking in a xHE-AAC track backed by a SourceBuffer
  • Fixed starting audio playback in Safari when the device is locked
  • Fixed playback for video when the timeline sometimes goes backward at the start of playback
  • Fixed capturing and rendering audio simultaneously


  • Fixed flickering when rendering overlapping negative z-index layers
  • Fixed disappearing multi-column content inside a fixed position container when scrolling
  • Fixed images displayed in Reader not appearing in a print job or PDF export


  • Fixed missing text in a sign-in sheet when registering a passkey with syncing platform authenticator disabled if Touch ID is not setup

Web Animations

  • Fixed computing implicit keyframes when a 0% and/or 100% keyframe is defined but only specifies a timing function


  • Fixed communication between BroadcastChannel instances in distinct opaque origins

Web Inspector

  • Fixed resources from memory cache showing empty content in Network, Sources, and Search tabs


If you have bug fixes you would like to see addressed, or other ideas, including features you would like to see implemented in WebKit, file a WebKit bug report. Filing issues really does make a difference. We also welcome your feedback on the Safari user interface. And you can send a tweet to @webkit, @jensimmons or @jonathandavis to share your thoughts on this release. We love to hear from you.

Download the latest Safari Technology Preview to stay at the forefront of the web platform and to use the very latest Web Inspector features.

And More

For more information, read the Safari 15.6 release notes.

These features were first released in Safari Technology Preview: 146, 147, 148.