504 Gateway Timeout: What Timed Out and How to Fix It

504 Gateway Timeout appears when a proxy or gateway gives up waiting for the server behind it. The request reached your app, but no answer arrived before the proxy's time limit, often 60 seconds. Slow database queries, calls to a slow outside API, and work that should run in the background are the usual causes.

Default time limits that produce a 504 or similar
Layer	Default limit	What you see
Nginx proxy_read_timeout	60 seconds between reads	504 Gateway Time-out
AWS ALB idle timeout	60 seconds	504 from the load balancer
Amazon API Gateway (REST)	29 seconds integration timeout	504 Endpoint request timed out
Vercel function	Your plan's or maxDuration setting	504 FUNCTION_INVOCATION_TIMEOUT
Cloudflare proxy	100 seconds on most plans	Error 524, Cloudflare's own timeout code

Updated October 28, 2026

Raising a timeout is tempting and sometimes right, but it usually hides the real problem. A request that needs more than a minute will also be slow for every visitor, tie up a worker, and fail again under load. The better fix is to find why the request is slow, then make it fast or move it out of the request.

Measure first, then raise one limit

Time the slow request against the app

Run this on the server so the network is not part of the measurement.

curl -s -o /dev/null -w 'status %{http_code} in %{time_total}s\n' http://127.0.0.1:3000/reports/monthly

A longer timeout for one Nginx location

Scope the change to the slow path so the rest of the site keeps failing fast.

location /reports/ {
    proxy_pass http://127.0.0.1:3000;
    proxy_read_timeout 180s;
    proxy_send_timeout 180s;
}

Fixes by platform

Nginx: proxy_read_timeout counts the time between two reads from the upstream, not the whole response, so streaming a little data keeps a long response alive. PHP behind Nginx has its own limits, max_execution_time and the FastCGI read timeout, and the lowest one wins.

Vercel: each function has a maximum duration set by your plan and the maxDuration option. Long tasks should hand off to a background job and let the page poll for the result.

Amazon API Gateway: REST APIs stop waiting for an integration after 29 seconds by default, so long work must be asynchronous: accept the job, return 202, and report the result later.

Make timeouts line up

When several layers each have a limit, the shortest one decides. A 120 second Nginx timeout does nothing behind a 60 second load balancer. List every layer from the browser to the database and make each timeout a little longer than the one inside it.

On a site hosted by We.Inc there is no web server, PHP process or function timeout of your own to tune. If a page on a We.Inc site returns this code, send support the address and the time so we can check our side.

How it works

Find the exact URL that times out and how long it takes against the app directly.
Check which layer cut it off: web server, load balancer, platform or CDN.
Profile the slow request: database queries, outside API calls, large file work.
Speed it up or move it to a background job; raise the one limit only if the work must stay in the request.

Tips

Time the request with curl -w '%{time_total}' against the app's own address to separate app slowness from network trouble.
Add timeouts to your own calls to outside APIs, shorter than the proxy's, so your app can return a clear error instead of a 504.
Report generation, video processing and bulk email belong in a queue with a job status page, not in a web request.
A database query that was fast with little data can slow down as tables grow; check for missing indexes first.

Frequently asked questions

What does 504 Gateway Timeout mean?

A server acting as a gateway or proxy did not get a timely response from the server it was forwarding to. The upstream may still finish the work, but the visitor gets the error.

How do I fix 504 Gateway Timeout in Nginx?

First make the slow endpoint faster. If it genuinely needs longer, raise proxy_read_timeout for that location only, for example to 180s, and check that any load balancer in front allows the same time.

Why does my Vercel function return 504?

It ran past its maximum duration, shown as FUNCTION_INVOCATION_TIMEOUT. Set maxDuration within your plan's limit, or split the work and run it in the background or a queue.

Is Cloudflare error 524 the same as 504?

It is Cloudflare's version of the same problem: Cloudflare connected to your server, but no HTTP response arrived within its timeout, 100 seconds by default. Fix the slow origin request, or move long jobs off the proxied path.

Can a visitor fix a 504?

No. Reloading may work if the slowness was brief. Repeating a form submission that timed out can create duplicates, so check whether the action went through first.

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