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WebKitSaron Yitbarek19 min readrelease notesintermediate

Release Notes for Safari Technology Preview 251

Read on webkit.org

Summary

Safari Technology Preview 251 introduces new CSS features like `@supports at-rule()` and `object-view-box`, alongside new JavaScript capabilities including `Iterator.prototype.includes()` and WebAssembly Memory64. This release also includes numerous bug fixes across HTML, CSS, and Canvas, and deprecates several non-standard CSS properties.

  • Safari TP 251 adds `@supports at-rule()` for testing CSS at-rule support and `object-view-box` property.
  • New CSS functions like `random()`, `random-item()`, `ident()`, and `inherit()` are now supported.
  • JavaScript gains `Iterator.prototype.includes()`, `join()`, `chunks()`, `windows()`, and `zip()`.
  • WebAssembly Memory64 and `import defer` for deferred module evaluation are now supported.

Frontend developers and web platform enthusiasts should review these notes to prepare for upcoming browser capabilities and ensure compatibility with evolving web standards.

6/10
frontendjavascriptbrowsercssweb platformwebassembly

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