417 Expectation Failed
4xx Client Error
RFC 9110
The server can't meet the expectation you declared.
What 417 Expectation Failed means {#what}
The server can’t fulfill the requirements indicated in the Expect request header — typically Expect: 100-continue. The client should retry without the Expect header.
When you’ll see a 417 {#when}
- Older servers that don’t support
Expect: 100-continue - Rarely in modern setups