Quality & errors · glossary

HTTP 407 Proxy Authentication Required

HTTP 407 Proxy Authentication Required is the status a proxy returns when a request arrives without valid proxy credentials: no Proxy-Authorization header, a wrong username or password, or a source IP that is not whitelisted when whitelisting is the only method configured. It is the proxy's counterpart of 401 and means the request never left the gateway; fixing the credentials or the whitelist resolves it.

1 min read Also called 407 error, proxy authentication required Updated

Authentication All terms

Common causes#

  • Credentials pasted with a trailing space or newline.
  • Special characters in the password not URL-encoded in a proxy URL.
  • The client sends credentials only after a challenge, and the tool does not handle the 407 round trip; pre-emptive Proxy-Authorization fixes it.
  • A rotated password: the old one expired after the grace period.
  • Whitelist mode with a changed source IP.

Quick check#

cURL prints the gateway answer
curl -v -x http://USER:[email protected]:9000 https://api.ipify.org

How it works at ProxShift#

ProxShift answers 407 with the code invalid_credentials; the dashboard shows the current pair, a rotated password keeps working for ten minutes, and whitelisted addresses need any username to carry parameters.

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