HTTP 103 — Early Hints

Used to return some response headers before final HTTP message

When to use it

Use status 103 when this is the correct HTTP response semantic: Used to return some response headers before final HTTP message

Request and response example

POST /uploads HTTP/1.1
Host: api.example.com
Expect: 100-continue

HTTP/1.1 103 Early Hints

Related status codes

100, 101, 102

References

MDN · RFC 9110