---
title: "306 (Unused) — what it means and how to fix it"
description: "A reserved code that was used in an old draft and is now permanently unassigned. What causes an HTTP 306, what to try as a visitor, and what to check if it is your own site."
url: https://atoneplace.net/error/306/
site: "At One Place"
---

# HTTP 306 — (Unused)

**HTTP 306: (Unused)**

A reserved code that was used in an old draft and is now permanently unassigned.

## What 306 actually means

This number was allocated to a proposal called "Switch Proxy" in an early HTTP/1.1 draft and dropped before the specification was finished. It is reserved so nothing else can claim it, and it has no meaning. A server sending a 306 is broken or lying; clients treat it as they would any unrecognised 3xx, which means the same as 300.

## Common causes

- A non-conforming server or a deliberately malformed response
- A test suite or fuzzer exercising unusual status codes

## If you're just trying to view the page

1. Nothing you can do — the server is sending an invalid response
2. Try the site again later or contact its owner

## If it's your site

1. Never emit 306; pick a real code from the registry
2. Clients should treat an unrecognised 3xx as a generic 300 and not follow anything automatically

## Reference

- **Status code:** 306
- **Reason phrase:** (Unused)
- **Category:** 3xx — Redirection
- **Defined in:** RFC 9110 §15.4.7

## Common questions

### What does HTTP 306 mean?

A reserved code that was used in an old draft and is now permanently unassigned. This number was allocated to a proposal called "Switch Proxy" in an early HTTP/1.1 draft and dropped before the specification was finished. It is reserved so nothing else can claim it, and it has no meaning.

### How do I fix a 306 error?

Nothing you can do — the server is sending an invalid response

### Is 306 a client error or a server error?

306 is in the 3xx range, which means redirection. It is not an error at all.

## Related pages

- [301 Moved Permanently](https://atoneplace.net/error/301/)
- [302 Found](https://atoneplace.net/error/302/)
- [304 Not Modified](https://atoneplace.net/error/304/)
- [307 Temporary Redirect](https://atoneplace.net/error/307/)
- [308 Permanent Redirect](https://atoneplace.net/error/308/)
- [303 See Other](https://atoneplace.net/error/303/)
- [300 Multiple Choices](https://atoneplace.net/error/300/)
- [305 Use Proxy](https://atoneplace.net/error/305/)

## Sources

- Hypertext Transfer Protocol (HTTP) Status Code Registry — IANA (https://www.iana.org/assignments/http-status-codes/)
- RFC 9110: HTTP Semantics — IETF (https://www.rfc-editor.org/rfc/rfc9110.html)