407 Proxy Authentication Required

4xx Client error

A proxy in between wants authentication first.

On the wireHTTP/1.1 407 Proxy Authentication Required
Code407
Is it an errorYes — this is an error
Category4xx Client error

The problem is on the request side; sending the same thing again will fail again.

How to read this

  • The first digit of a status code carries the meaning: 4 means the request, 5 means the server.
  • 404 means "not there"; 403 means "there, but not for you". Swapping them makes debugging slower.
  • Header names are case-insensitive — Content-Type and content-type are the same header.
  • Caching and CORS problems usually come down to one header line, visible in the browser’s network tab.

Frequently asked questions

Q. What does HTTP 407 Proxy Authentication Required mean?

A proxy in between wants authentication first.

Q. What does 407 Proxy Authentication Required look like on the wire?

It travels as HTTP/1.1 407 Proxy Authentication Required

Q. Is 407 Proxy Authentication Required an error?

Yes. A code starting with 4 blames the request; one starting with 5 blames the server.

Q. What group does 407 Proxy Authentication Required belong to?

The 4xx client error group; the rest of that group is listed further down.

Same group

Reference docs