100 Continue

Look up a status, pick the right one for an API, or hit a live endpoint that actually returns it. Add ?code=418 to this URL and the response is that status — useful for curl, interceptors, and “what does my client do on 503?” Nothing here phones home except the Try it fetch to this same page.

Which class?

100

Continue

Informational · RFC 9110

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

When to use

Automatic when a client sends Expect: 100-continue with a large body. You almost never return this from application code.

Don’t

Do not use it as a business-level “keep going” signal. Browsers and PHP cannot usefully simulate it.

Live URL

curl -i https://corecoding.com/utilities/http-status.php?code=100


    

Code use cases