Signal Forms, an experimental library for managing forms state with signals, provides a new scalable, composable, and reactive forms experience built on Signals. With Signal Forms, the Form model is defined by a signal that automatically syncs with the form fields bound to it. This allows for an ergonomic developer experience with full type safety for accessing form fields. Centralized schema-based validation logic is built-in. The Angular team added that, with signals driving modern Angular state management, zone.js no longer is needed for change detection. Zoneless change detection, introduced experimentally in Angular v18, progressed through Developer Preview in Angular v20 and reached stability in Angular v20.2. Angular traditionally used zone.js to track changes in applications, but zone.js has performance drawbacks, the Angular team said. Zoneless change detection offers benefits including better core web vitals, native async-await, ecosystem compatibility, reduced bundle size, easier debugging, and better control, the team said.
Also featured in Angular v21 is a developer preview of Angular Aria, a library for common UI patterns. The library is a collection of headless, accessible directives that implement common WAI-ARIA patterns. These directives handle keyboard interactions, ARIA attributes, focus management, and screen reader support, according to the Angular team. Developers just have to provide the HTML structure, business logic, and CSS styling. To start, developers have access to eight UI patterns encompassing 13 components that are completely un-styled and can be customized. The patterns include Accordion, Combobox, Grid, Listbox, Menu, Tabs, Toolbar, and Tree. Elsewhere in Angular v21, the Vitest testing framework has been made the default test runner and has been promoted to stable status.
