Vercel · infra · fg-0248

Vercel Function returns 504 FUNCTION_INVOCATION_TIMEOUT after 10 or 15 seconds on an older project

504: GATEWAY_TIMEOUT with code FUNCTION_INVOCATION_TIMEOUT

Verified 2026-10-15 · Confirmed by 0 builders · Trust 50/100

Cause

The 300 second default applies only when Fluid compute is on, and Fluid compute is enabled by default only for projects created on or after April 23, 2025. Older projects keep the legacy short defaults until Fluid is switched on or maxDuration is set.

Fix

Turn on Fluid compute for the project and redeploy, or set maxDuration on the function within your plan maximum.

Apply

// vercel.json
{ "fluid": true }

// or in an App Router route file
export const maxDuration = 300;

Affects: Projects created before 2025-04-23 without Fluid compute; Hobby legacy default 10 s (max 60 s), Pro legacy default 15 s

Sources

• https://vercel.com/docs/fluid-compute
• https://vercel.com/docs/functions/limitations
• https://vercel.com/changelog/vercel-functions-for-hobby-can-now-run-up-to-60-seconds

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