HTTP Status Code 306 = “Unused”
306 is a reserved HTTP status code that is no longer used.
History
Originally, it was intended for:
- “Switch Proxy”
The idea was that the client should use a specific proxy server for future requests.
However, the status code was abandoned and reserved, so modern browsers and servers do not use it.
Current status
- Reserved by HTTP specification
- Not used in normal web development
- Browsers generally ignore it
- Rarely seen in real applications HTTP redirect family
306 belongs to the 3xx redirect category:
| Code | Meaning |
|---|---|
301 | Moved Permanently |
302 | Found / Temporary Redirect |
303 | See Other |
304 | Not Modified |
305 | Use Proxy |
306 | Unused |
307 | Temporary Redirect |
308 | Permanent Redirect |
Developer note
If your application returns 306, it is usually:
- A custom/internal status code
- Misconfigured server/framework
- Debug/testing response
- Proxy/server issue
You should replace it with a standard HTTP code.