HTTP 100 Continue

The server received the initial request headers and the client may continue sending the request body.

Use 100 Continue for an Expect: 100-continue handshake before a potentially large request body.

httpstatus codeinformational

Response (http)

HTTP/1.1 100 Continue

Use 100 Continue for an Expect: 100-continue handshake before a potentially large request body.

Common mistakes

Sending 100 Continue when the client never asked for it with Expect: 100-continue.

Registry reference: RFC9110, Section 15.2.1

Sources