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Vercel build suddenly on Node.js 26? Why it happened and how to pin a version

Ship ItChecked against the official source

Source checked 30 Oct 2026 · Published 30 Oct 2026 · Last reviewed 30 Oct 2026 · By Ctrl+Z Therapy (how we test)

The short answer

Vercel's changelog of October 29, 2026 says Node.js 26 LTS is generally available for builds and Vercel Functions, and it's the default for all new projects. Existing projects move too: if engines.node in your project's package.json allows 26 (for example, a range of 20 or higher), your Node.js builds on Vercel use 26 on the next deployment.

What to do

  1. To choose the version yourself, set engines.node in package.json to the major version you want. Vercel's docs list 26.x (default), 24.x and 22.x; only major versions are available.
  2. Keep in mind that the version in package.json overrides the Node.js Version in Project Settings.
  3. To check which version a build uses, run node -v in the Build Command.

Good to know

  • One behavior change: built-in fetch now uses HTTP/2 by default with servers that support it. To keep HTTP/1.1 in Functions, set the VERCEL_FETCH_DISABLE_H2 environment variable to 1 and redeploy.
  • Minor and patch updates to Node.js 26 roll out automatically.

Source

Checked on 30 Oct 2026. Prices, limits and settings change, so check the source before you rely on them.

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