To help you become more efficient, Web Inspector includes keyboard shortcuts for many commonly used actions.

WebKit now supports paginated scrolling through CSS Snap Points — making sophisticated paginated scrolling a snap.

Web Inspector includes a new tool to help locate and resolve rendering performance issues — in addition to the familiar event-based timelines.

Styles Sidebar Refinements in Web Inspector

Learn about the various enhancements we made to Web Inspector’s Style sidebar in Safari 9 — such as text filtering and intelligent editing.

JavaScript Type and Code Coverage Profiling

Web Inspector now has two great tools designed to make debugging JavaScript programs easier: the Code Coverage Profiler and the Type Profiler.

WebKit supports many selectors defined in the draft of CSS Selectors Level 4 — like matches(), not(), nth-child(…of…) and nth-last-child(…of…).

The proposed backdrop-filter property adds a feature that designers have been demanding for some time — allowing for beautiful blur effects.

Web Inspector’s core functions have been divided out into their own tabs — like the tabs in Safari.

On iOS 9 and OS X El Capitan, specifying “font-family: -apple-system” allows you to use Apple’s new system font: San Francisco.

JetStream 1.1 fixes bugs in two existing tests and adds a new test to replace the oldest and smallest test in the latency component.

We improved both the Console and Object views to make it more powerful and fun to use.

Describing content blocking rules in a structured format ahead-of-time, rather than running extension-provided code.