1xx Informational

HTTP 100 Continue

The server has received the request headers and the client should proceed to send the request body.

When is 100 used?

  • Large POST requests where client sends 100-continue header first
  • Upload validation before sending large payloads

How to handle a 100 response

Clients rarely see these directly; HTTP libraries handle them before the final response arrives, and servers usually send them automatically.

Check the status code a URL returns from the command line:

curl -s -o /dev/null -w "%{http_code}\n" https://example.com

Frequently Asked Questions

What does HTTP 100 mean?

100 Continue: The server has received the request headers and the client should proceed to send the request body.

Is 100 an error?

No. 100 is in the 1xx Informational class. Informational responses: the request was received and processing continues.