# Vercel Bun 1.4 is now available in Vercel Functions

- Product: Vercel (https://whatsnew.fyi/product/vercel)
- Vendor: Vercel
- Date: 2026-08-20
- Original notes: https://vercel.com/changelog/bun-1-4-is-now-available-in-vercel-functions
- Permalink: https://whatsnew.fyi/product/vercel/releases/2026-08-20-bun-1.4-is-now-available-in-vercel-functions

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

---

Vercel Functions now support the new Bun 1.4 release , a rewrite of Bun from Zig to Rust, with over 2,900 issues resolved, more than 1,500 additional Node.js compatibility tests passing, and new featu…

- **added** — Support for Bun 1.4 runtime in Vercel Functions
- **changed** — Bun rewritten from Zig to Rust with over 2,900 issues resolved
- **changed** — More than 1,500 additional Node.js compatibility tests passing