• Home
  • macOS
  • News
  • Safari Technology Preview 115 Release Offers Bug Fixes and Performance Improvements

Safari Technology Preview 115 Release Offers Bug Fixes and Performance Improvements

Safari Technology Preview 115 Release Offers Bug Fixes and Performance Improvements

Apple on Thursday released Safari Technology Preview 115, the latest version of their developer preview web browser. The preview version of Apple’s popular browser offers developers and other interested users the ability to try out features that may or may not, debut in future public release versions of Safari.

Release 115 includes bug fixes and performance improvements for Web Audio, JavaScript, Web API, Media, CSS, WebAuthn, Selection API, and WebRTC.

The current ‌Safari Technology Preview‌ release is built on the new Safari 14 update included in macOS Big Sur.

Release 115

Web Audio

  • Enabled the modern unprefixed WebAudio API
  • Changed AnalyserNode to downmix input audio to mono
  • Changed AnalyserNode’s getByteFrequencyData() and getFloatFrequencyData() to only do FFT analysis once per render quantum
  • Changed AudioBufferSourceNode to update grain parameters when the buffer is set after rendering has started
  • Updated AudioParam.setValueCurveAtTime() to have an implicit call to setValueAtTime() at the end
  • Updated AudioParams with automations to process timelines
  • Fixed BiquadFilterNode’s lowpass and highpass filters
  • Fixed Web Audio API outputting silence for 302 redirected resource
  • Made AudioBufferSourceNode loop fixes
  • Changed to properly handle AudioParam.setTargetAtTime() followed by a ramp
  • Improved AudioBufferSourceNode resampling


  • Fixed BigInt to work with Map and Set
  • Enabled Intl.DateTimeFormat dayPeriod
  • Updated Intl rounding behavior to align with specifications update
  • Updated functions to consistently enumerate length property before name property
  • Updated Array.prototype.sort to be consistent with specifications


  • Performance.navigation and Performance.timing are incorrectly exposed to workers
  • Update User Timing interfaces to User Timing Level 3
  • Fixed visibilitychange:hidden event to fire during page navigations


  • Added support for HTMLMediaElement.setSinkId


  • Changed to clear the override width to properly compute percent margins in CSS Grid
  • Implemented the CSS math-style property


  • Changed to not set the UV option if the authenticator doesn’t support it

Selection API

  • Fixed selectAllChildren to return InvalidNodeTypeError when passed a DocumentType node
  • Improved VisibleSelection, FrameSelection, and DOMSelection to preserve anchor and focus


  • Updated toRTCIceProtocol to handle ssltcp candidates

The preview is available for both macOS Catalina and macOS Big Sur.

While the preview is intended for use by developers and advanced users, in order to provide Apple with feedback on the development of the Safari browser, it can be run side-by-side with the release version of Safari. The app doesn’t require a developer account to download and install. For more information, visit the Safari Technology Preview website.