HTTP 100 Continue

What 100 means

A client that sends Expect: 100-continue waits for this interim response before uploading a large body, which avoids sending data the server would reject anyway.

Common causes

• The client sent an Expect: 100-continue header.
• A large upload is being negotiated before the body is sent.

How to fix it

1. No action is needed; the final status follows after the body is sent.
2. If uploads stall, check that proxies forward 100 Continue correctly.

How to check a status code

Enter a URL in the HTTP Status Checker to see its status code, every redirect hop, and response time. For redirect-heavy pages, the Website Speed Test shows how much time redirects add.

FAQ

What does HTTP 100 mean?

100 Continue is a 1xx informational status code. The server received the request headers and the client should send the request body.

What causes a 100 error?

The client sent an Expect: 100-continue header. A large upload is being negotiated before the body is sent.

How do I fix HTTP 100?

No action is needed; the final status follows after the body is sent. If uploads stall, check that proxies forward 100 Continue correctly.