Vite 8.1.5

Let's Not Get Carried Away

Vite 8.1.5 landed on July 16, 2026, and let's be honest: this is not the release that will make headlines. It is a patch. A solid, necessary patch, but a patch nonetheless. If you were hoping for the rolldown production-build milestone or the long-promised Rust plugin API, you will have to wait a bit longer.

What Actually Changed

The changelog is dominated by bug fixes — 7 to be exact. Nothing here will break your build, but a few items deserve a closer look before you blindly run that upgrade command.

• bundled-dev: duplicated buildEnd — A fix for a subtle bug where buildEnd was firing twice in bundled dev mode. Good to have fixed, but it is the kind of thing you would only notice if you were hooking into that lifecycle.
• SSR switch-case declarations — Variable declarations inside switch/case blocks were leaking to the enclosing function scope in SSR mode. This fix scopes them correctly. If you use SSR with complex switch statements, test this upgrade carefully.
• Module runner crash — A stack-trace source-mapping crash when globalThis.Buffer was absent. Edge case, but nasty if you hit it.
• CJS dynamic import interop — The optimizer now respects the importer module format when handling dynamic imports of CJS dependencies. This could affect projects mixing ESM and CJS.

The Upgrade Caveat

There are no breaking changes in 8.1.5, which is the good news. The bad news? The changelog is almost entirely dependency bumps and internal refactoring. The onLog replacement for the deprecated onwarn API that shipped in 8.1.4 continues to settle. If you have custom build plugins relying on onwarn, they should already have been migrated.

Should You Upgrade?

Short answer: yes, but do not rush. Vite 8.1.5 is a maintenance release. The fixes are legitimate, but unless you are hitting one of the specific bugs listed above, there is no fire drill here. Run your test suite, check your CI, and deploy when you are comfortable. The real excitement — the rolldown production build — is still on the horizon.

Upgrade with npm create vite@latest or npm update vite.