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npm / lit

lit

What changed in lit 3, from its official release notes, upgrade guides and advisories. Sources checked 2026-10-23.

5 breaking1 deprecations5 fixes and other

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

npx @unstale/cli init

@unstale/cli 0.2.4 on npm

lit 311 changes

Breaking changes 5

  • Generated reactive-property accessors now wrap user accessors and call this.requestUpdate() in the setter; with noAccessor: true, users must call it themselves to trigger an update.

    3.0.0release notes

  • Experimental hydrate modules were removed; they are available from @lit-labs/ssr-client.

    3.0.0release notes

  • IE11 is no longer supported.

    3.0.0release notes

  • Lit 1 to Lit 2 migration warnings were removed.

    3.0.0release notes

  • The deprecated queryAssignedNodes behavior and arguments were deleted; use @queryAssignedElements for selector-based usage.

    3.0.0release notes

Deprecations 1

  • Lit now warns when performUpdate() is overridden asynchronously.

    3.0.0release notes

Fixes and other changes 5

  • The ref directive now disconnects gracefully when its internal ref is undefined.

    3.3.3release notes

  • Decorators now work with the accessor keyword when experimentalDecorators is true.

    3.0.0release notes

  • The return type now includes undefined.

    3.0.0release notes

  • Its return type is now HTMLElement | DocumentFragment, matching ReactiveElement.renderRoot and lit-html's render() method.

    3.0.0release notes

  • The type is now HTMLElement | DocumentFragment, matching the return type of createRenderRoot() and lit-html's render() method.

    3.0.0release notes