Angular 16

Angular 16 made standalone APIs stable, allowing applications to use standalone components, directives, and pipes without relying on NgModules as the primary composition mechanism. It introduced the Signals reactive primitive and related APIs as developer-preview functionality, alongside utilities such as DestroyRef and takeUntilDestroyed for lifecycle-aware cleanup. The cycle also added developer-preview features for non-destructive server-side rendering hydration, required directive and component inputs, directive composition, and router-to-component input binding. These changes expanded Angular's options for reactive state management, SSR performance, component APIs, and incremental movement away from NgModule-based architecture, but several of the newer APIs were not yet final contracts. Angular is not AngularJS: AngularJS is a separate, earlier framework with its own versions and its own end of life. Teams running AngularJS should use /technology/angularjs instead.

Angular 16 has reached end of life, so applications remaining on it no longer receive upstream fixes for framework defects or security issues. The practical exposure grows when a dependency, browser behavior, build tool, or supported Node.js and TypeScript version moves on while the Angular 16 compatibility range remains fixed. Applications using developer-preview features from this cycle, particularly Signals or hydration, also carry migration risk because later Angular versions may have changed APIs, semantics, diagnostics, and recommended patterns before those features became stable. Staying can make future migration larger: library authors increasingly publish peer dependency ranges and build outputs aimed at currently supported Angular versions, and deferred upgrades tend to combine framework, TypeScript, Node.js, test tooling, and SSR changes into one harder-to-isolate project.

Plan a move from Angular 16 to a currently supported Angular major version using Angular's update guidance for the exact source and target versions. Before changing dependencies, inventory use of Signals, hydration, required inputs, directive composition, standalone migration output, custom builders, SSR, and Angular libraries with peer dependencies; treat preview-era usage as code requiring deliberate review rather than a mechanical version bump. Update the Angular CLI and Angular framework packages together, align Node.js, TypeScript, RxJS, and any test or build tooling with the target version's documented compatibility requirements, and run the provided migrations through the workspace package manager. Build and test production configurations as well as local development, with focused browser and server-rendering tests for hydration, routing, forms, and lifecycle cleanup. Resolve compiler diagnostics and deprecated APIs as part of the migration, then lock the resulting supported versions and add an ongoing upgrade cadence so the application does not accumulate another unsupported-version gap.