Multiple Choices

The request has more than one possible response. The client should pick one.

300 Multiple Choices means the server has more than one representation of the resource and wants the client to pick, like a document available in several formats or languages. In theory the body lists the options and a Location header can suggest a preferred one. In practice servers negotiate formats through headers instead, so a genuine 300 is vanishingly rare.

What 300 looks like on the wire

GET /downloads/app HTTP/1.1
Host: example.com

HTTP/1.1 300 Multiple Choices
Content-Type: text/html
Link: </downloads/app-x64.deb>; rel="alternate"
Link: </downloads/app-x64.rpm>; rel="alternate"

About 3xx Redirection

Further action is needed to complete the request, usually following a redirect to another URL.

Where it's defined

300 Multiple Choices is defined in RFC 9110 §15.4.1. MDN's 300 reference covers browser behavior and examples.