Vue 3.0

Vue 3.0 was the first Vue 3 release line and introduced the Composition API as an alternative to the Options API, enabling reusable stateful logic through setup(), ref(), reactive(), computed(), and composables. It also replaced the Vue 2 global constructor pattern with application instances created by createApp(), added Teleport, Fragments, Suspense, and multiple v-model bindings, and changed several template and component behaviors. Internally, Vue 3 adopted a rewritten, proxy-based reactivity system and a redesigned renderer intended to improve runtime efficiency and enable better tree-shaking. Migration from Vue 2 was not fully drop-in: applications using filters, instance event APIs such as $on and $off, keyCode modifiers, or assumptions about root-element and attribute behavior required changes.

Vue 3.0 has reached end of life. Staying on this line leaves a team without maintenance updates for defects or security issues in the framework line and separates the application from later Vue 3 compatibility, tooling, TypeScript, performance, and developer-experience improvements. The practical risk is not only framework exposure: dependencies, build tooling, testing tools, component libraries, and Vue language tooling generally target later Vue 3 releases, so upgrades elsewhere can increasingly require version pinning or custom workarounds. Because 3.0 was the initial Vue 3 line, it also lacks subsequent fixes and refinements to APIs introduced during the Vue 2-to-3 transition.

Plan an upgrade to a currently supported Vue 3 release rather than treating Vue 3.0 as a stable destination. First inventory the Vue runtime, compiler, router, state-management package, component libraries, Vite or other build tooling, test tooling, and editor integration; identify packages that impose Vue peer-dependency constraints. Upgrade the Vue runtime and compiler together, then update related first-party packages to compatible versions. Run the application’s test suite and manually verify components that use Composition API patterns, Teleport, Suspense, multiple v-model bindings, custom directives, render functions, and third-party UI libraries. If the application was migrated from Vue 2 with compatibility-mode settings or transitional workarounds, remove or resolve those deliberately and use Vue’s migration guidance to identify remaining legacy patterns. Pin and test the resulting dependency set in CI before deploying.