Chrome 152 Ships New Pseudo Elements and a CPU Performance API

Chrome 152 reached stable in the last week of August 2026, and it brings three changes worth a developer's attention: expanded support for the ::backdrop, ::scroll-marker, and ::view-transition pseudo-elements, a new CPU Performance API, and a Connection Allowlists security header for installed web apps.

The pseudo-element work matters most for anyone building scroll driven interfaces or custom view transitions, both of which have gone from experimental to genuinely usable across the last year of Chrome releases. Wider support for ::scroll-marker in particular makes it easier to build a native feeling scroll indicator, the kind of small polish detail that used to need a JavaScript library and now needs a CSS rule.

The CPU Performance API is the more structural change. It lets a web app query the device's rough performance tier before deciding how much work to do, rendering a lighter 3D scene on a budget phone rather than a full quality one that will just stutter. Native apps have had access to this kind of device tiering for years. The web has mostly had user agent sniffing, which tells you what browser someone is running rather than what their hardware can actually handle. A proper performance signal means fewer guesses.

Connection Allowlists lets an installed web app declare which origins it is allowed to talk to, tightening what a compromised or malicious script inside that app could actually reach. It is aimed squarely at progressive web apps asked to behave more like trusted native software, and it closes a gap that has made some enterprises nervous about installing web apps at all.

None of these are dramatic individually. Together they are Chrome continuing to close the list of reasons a genuinely native-feeling app still has to be built as one, one performance signal and one security boundary at a time.