The URL is longer than the server will handle.
When to use it
Huge query strings. Move the data into a POST body.
Common causes and fixes
The request URL exceeds a limit. Typical triggers: huge query strings built from filters or ID lists, base64 data in the URL, redirect loops that append a parameter each round (a returnUrl nested inside a returnUrl), and stacked tracking parameters. nginx answers 414 when the request line doesn’t fit large_client_header_buffers, 8k by default, and Apache’s LimitRequestLine is 8190 bytes.
Keep URLs under about 2,000 characters to be safe across browsers, CDNs, analytics and log tools; Cloudflare caps URLs at 16 KB. The fix is moving the data into a POST body, or posting the filter to a search endpoint that returns a short ID to put in the URL. Raising server limits works, but every proxy in the chain has its own limit.
Client error (4xx)
4xx codes are client errors: the request itself is wrong, unauthorised or points at something that isn’t there. Retrying the same request won’t help.
What it looks like
HTTP/1.1 414 URI Too LongHow to send it
| Node.js / Express | res.status(414).end() |
|---|---|
| Python / Flask | return '', 414 |
| nginx | return 414; |
How to check it
curl -s -o /dev/null -w "%{http_code}\n" https://example.com/