Bun runtime now supports large functions and extended max duration
Bun on Vercel now runs 5GB packages for 30 minutes—a shift for compute-heavy AI workloads.
Why it matters
Vercel's Bun runtime expansion enables practitioners to deploy larger AI models and longer-running inference tasks (RAG, batch processing, fine-tuning prep) without splitting across multiple functions or switching platforms.
The key facts
12 to knowPackage size limit raised from 250MB to 5GB uncompressed
Max duration extended from 800 seconds (13 min) to 1800 seconds (30 min)
Features available for Pro and Enterprise teams
New projects auto-enrolled in large functions beta; existing projects opt-in via VERCEL_SUPPORT_LARGE_FUNCTIONS=1
Per-function duration control via vercel.json (not project-level default)
Unavailable during beta on Secure Compute or Static IP projects
Feature previously only on Node.js and Python; now in Bun runtime
Package size limit: 250MB → 5GB uncompressed
Max duration: 800 seconds → 1800 seconds (30 minutes) for Pro/Enterprise
Available as beta; new projects auto-enrolled, existing projects opt-in
Per-function duration settings via vercel.json
Published August 24, 2026
Go to the source
Vercel Blogvercel.com
Publisher excerpt: The on Vercel Functions now supports larger package sizes up to 5GB uncompressed and extended max duration for up to 30 minutes, two betas that previously ran on Node.js and Python only.Bun runtime Large functions raise the standard 250MB package size limit to 5GB, and extended max duration raises…