Node.js 26 LTS is now Generally Available on Vercel

Node.js 26 LTS is now generally available for builds and Vercel Functions, replacing previous versions as the default for new projects. Developers can enable it automatically if their package.json allows version 26 or later, such as >=20, by deploying the next update. Manual activation requires setting engines.node to 26.x in package.json and redeploying the project. The update ensures consistency across Vercel’s infrastructure while maintaining backward compatibility for existing configurations.

HTTP/2 is enabled by default for built-in fetch using Undici 8, improving performance for Functions that interact with APIs or databases over HTTP. This feature allows multiple requests to share a single connection when supported by the server, reducing latency in data exchanges. Developers can opt out by setting VERCEL_FETCH_DISABLE_H2 to 1 in environment variables and redeploying. The change applies to both new and existing Functions unless explicitly disabled.

The Temporal API introduces immutable time-handling alternatives to the traditional Date object, offering built-in support for time zones and calendars. This addition simplifies complex date manipulations and reduces errors in applications requiring precise time tracking. The feature is now available in Node.js 26 LTS deployments on Vercel without additional configuration. Developers can integrate it directly into their projects for improved date management.

Node.js 26 LTS includes V8 version 14.6, which introduces new JavaScript features such as Map.prototype.getOrInsert(). This method retrieves an existing value or inserts a default when a key is missing, streamlining data handling in applications. Minor and patch updates for Node.js 26 will roll out automatically for builds and Functions. Prebuilt deployments require Vercel CLI version 65.8.0 or later to utilize Node.js 26 Functions.