HTTP 306 (Unused)

Updated October 18, 2026Free mock REST & WebSocket APIs

HTTP 306 (Unused) — Reserved: it was used in a draft specification and is no longer used.

Try it: get a real 306 response

Our test endpoint answers every request with 306 (Unused).

curl -i https://mockfox.dev/api/status/306

Use it in tests, health-check monitors or to see how your client handles a 306. Add ?delay=2000 to slow it down.

What does HTTP 306 mean?

Code 306 was "Switch Proxy" in an early draft and is now permanently reserved so nobody reuses it. You should never see it in the wild.

Also known as: Switch Proxy.

Visitors: Browsers handle redirects automatically. If you're stuck in a loop, clear the site's cookies and cache.
Developers: Check the Location header and test redirects with curl -I. Prefer 301/308 for permanent moves and 302/303/307 for temporary ones.

HTTP/1.1 306
Content-Type: application/json

{"status":306,"error":"(Unused)"}

3xx Redirection: Further action (usually following a Location header) is needed to complete the request. See the full list of HTTP status codes.

What does HTTP 306 (Unused) mean?

Reserved: it was used in a draft specification and is no longer used.

Is 306 an error?

No. 306 is a redirection status — the client needs to take another step, usually following the Location header.

Where is 306 defined?

In RFC 9110 §15.4.7. It's listed in the IANA HTTP Status Code Registry, but marked deprecated or reserved.

How can I test how my app handles a 306?

Call https://mockfox.dev/api/status/306 — it responds with 306 to any method, with CORS enabled. Add ?delay=2000 to simulate a slow response.