Running FFmpeg on Vercel? You will hit a wall.
A serverless function is built for a quick request, not a CPU-bound video encode. Bundle FFmpeg into it and it works for a three-second clip, then times out on anything real. The fix is not a bigger function: keep it thin and call a hosted FFmpeg API that returns a finished file URL.
Four walls, and you hit them fast.
None of these are bugs you can configure away. They are what a serverless platform is, by design.
Keep the function thin. Move the encode off Vercel.
Your route handler does one cheap thing: it forwards the input and typed options to KinoPipe and returns the result. The encode runs on managed FFmpeg 9 workers, off your function's timeout and off your Vercel bill.
8.2s
p50 render for a 1080p H.264 edit
100%
success rate across 325 benchmark runs
<1s
time your Vercel function spends
FFmpeg 9 render benchmark, August 2026: cold, warm and burst phases on production recipes.