4xx Client ErrorHTTP Status Code Reference
HTTP 417 Expectation Failed— What It Means, Causes & How to Fix It
The expectation given in the Expect header could not be met by the server. The server cannot meet the requirements indicated by the Expect request-header field.
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Common Causes
- Server doesn't support Expect: 100-continue
- Proxy or gateway not forwarding the Expect header
- Server unable to meet the stated expectation
How to Fix
- 1Remove the Expect header from your request
- 2Send the request body directly without waiting for 100 Continue
- 3Check if intermediary proxies support the Expect header
Example
HTTP 417 Expectation Failed
POST /upload HTTP/1.1 Expect: 100-continue → 417 Expectation Failed → Server does not support this expectation
Related Client Error Codes
400
Bad Request
401Unauthorized
402Payment Required
403Forbidden
404Not Found
405Method Not Allowed
406Not Acceptable
407Proxy Authentication Required
408Request Timeout
409Conflict
410Gone
411Length Required
412Precondition Failed
413Content Too Large
414URI Too Long
415Unsupported Media Type
416Range Not Satisfiable
418I'm a Teapot
421Misdirected Request
422Unprocessable Content
423Locked
424Failed Dependency
425Too Early
426Upgrade Required
428Precondition Required
429Too Many Requests
431Request Header Fields Too Large
451Unavailable For Legal Reasons
Commonly Referenced Status Codes
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