4xx Client Errors
HTTP 407 Proxy Authentication Required
The client must first authenticate itself with the proxy.
When is 407 used?
- Corporate proxy authentication
- Upstream proxy credential requirements
How to handle a 407 response
Inspect the request — URL, method, headers, credentials, and body. Retrying the same request unchanged will usually fail again; 429 is the exception, where you should wait for the Retry-After period.
Check the status code a URL returns from the command line:
curl -s -o /dev/null -w "%{http_code}\n" https://example.comHow to return 407 from your server
Node.js (Express)
res.status(407).json({ message: 'Proxy Authentication Required' });Python (Flask)
return {"message": "Proxy Authentication Required"}, 407Go (net/http)
w.WriteHeader(407)Frequently Asked Questions
What does HTTP 407 mean?
407 Proxy Authentication Required: The client must first authenticate itself with the proxy.
Is 407 an error?
Yes. 407 is in the 4xx Client Errors class. Client errors: the request is malformed, unauthorized, or targets something that does not exist.