What 414 URI Too Long means

414 URI Too Long means the request line (the URL with all query parameters) exceeds the server's parsing buffer. Typical limits are 4KB-8KB. This usually happens when GET requests are used to send what should be a POST body: large lists in query strings, encoded binary data in URLs, or query-string explosion from chained tracking parameters. The fix is almost always to switch to POST.

When servers should return it: Return 414 when the request URI exceeds the server's configured maximum.

Common causes

  • Massive query strings (hundreds of parameters)
  • Base64-encoded data in URL parameters
  • Tracking parameter sprawl (UTM + Google + Facebook + custom)
  • GET request being used where POST should be

How to fix 414 URI Too Long

  • Move data from query string to POST body
  • For search APIs, accept POST with JSON body for complex queries
  • Increase server limit (Nginx: large_client_header_buffers)
  • Strip unnecessary tracking parameters

Example response

HTTP/2 414
content-type: text/plain
URI too long

More references

For a one-page reference of all HTTP status codes, see the HTTP cheat sheet. For testing API responses, try the API Tester tool. For inspecting responses on the command line, the curl cheat sheet covers the most common flags.