npm / preact

preact

What changed in preact 10 to 11, from its official release notes, upgrade guides and advisories. Sources checked 2026-10-18.

1 breaking1 security5 behavior and defaults11 fixes and other

See which of these apply to your code, ranked, in your agent:

npx @unstale/cli init

preact 1116 changes

Errors that no boundary handles now log the component stack.
11.0.1release notes
Event listeners are keyed by prop name and have attach times stamped per listener.
11.0.1release notes
Ref cleanups stay on the element instead of the ref function.
11.0.1release notes
The imageRendering property is mapped to the image-rendering CSS property.
11.0.0release notes
Top-level Fragments no longer use cloneNode.
11.0.0release notes

Parked Suspense children are unmounted when their boundary unmounts.
11.0.1release notes
Types for preact/compat/scheduler are fixed.
11.0.1release notes
Types for preact/compat/server are fixed.
11.0.1release notes
Suspended hydration stays within a component's own $s range.
11.0.1release notes
CamelCase custom event names retain their casing.
11.0.0release notes
Insertion appends when the reference node lives in another container.
11.0.0release notes
Containers without an ownerDocument use the global document.
11.0.0release notes
Availability is checked on the container rather than globally.
11.0.0release notes
DOM nesting validation now stops at portal boundaries.
11.0.0release notes
Refs are re-attached when a suspended subtree reveals.
11.0.0release notes
Resuming into the DOM kept while a component was suspended is fixed.
11.0.0release notes

Preact has JSON VNode Injection issue
10.26.10, 10.27.3, 10.28.2security advisory