100 Continue
The 100 Continue status code is a 1xx intermediate status code instructing the client to resume transmission of the rest of the request message. As an intermediate status code, it is emitted before and in addition to a final, non-1xx status code.
It seen when handling uploads with Expect: 100-continue; where the client will transmit just the message headers, and wait for a 100 Continue intermediate status before uploading the message body.
Writing responses (servers)
This status code is used when handling requests with Expect: 100-continue, see the Expect header for usage.
Reading responses (clients)
If the client has sent a request with Expect: 100-continue, then upon receipt of 100 Continue, begin writing the request message-body. Otherwise, this intermediate status be ignored.
Overview table
- Name
- 100
- Message
- 100 Continue
- Description
- Begin uploading the request message-body.
- Specification
- RFC 7231: HTTP/1.1 Semantics and Content ยง6.2.1. 100 Continue
Example
HTTP/1.1 100 Continue
Implementation support
Node.js
Node.js has sufficient support for 100 to process to process 100-continue expectations. These requests will be emitted as a separate event, see Event: 'checkContinue' and response.writeContinue() for server support; and Event: 'continue' for client support.