Who sends a 407 status code?
An intermediate proxy, usually on a corporate or school network. The website you requested never saw the request, so its server is not the cause.
HTTP 407 PROXY AUTHENTICATION REQUIRED
Like 401, but the proxy needs credentials. 407 belongs to the 4xx client error class and is defined in RFC 9110.
Loading the workbench.
About HTTP 407
What Does HTTP 407 Proxy Authentication Required Mean?
Like 401, but the proxy needs credentials. The code is registered with IANA and defined in RFC 9110.
Client error: the request has a problem, so it cannot be fulfilled as sent. Every code from 400 to 499 shares that general meaning, so a client that does not recognise 407 must treat it like 400.
When Do You See a 407 Response?
407 Proxy Authentication Required works like 401, but the challenge comes from a proxy between the client and the origin, not from the website. You see it on corporate networks with authenticating proxies, in CI runners behind company firewalls, and with package managers such as npm or pip when proxy credentials are missing. The request never reached the destination server, so the target site is not involved at all.
How Do You Fix a 407?
The proxy must send a Proxy-Authenticate header naming the scheme it expects. Clients should supply credentials in Proxy-Authorization, usually by setting the proxy URL with credentials in the HTTPS_PROXY environment variable or the tool's proxy settings. Avoid embedding real passwords in shared scripts. For NTLM or Kerberos proxies, use a client or helper that supports those schemes, since Basic alone may be rejected.
What Does a 407 Response Look Like?
HTTP/1.1 407 Proxy Authentication Required
Proxy-Authenticate: Basic realm="corp-proxy"
Content-Length: 0407 is not cacheable by default: a browser or CDN stores it only when Cache-Control or Expires explicitly allows it.
To inspect a real one without sending it anywhere:
- Copy the response headers from your browser Network tab, or from
curl -i. - Paste them into the Header decoder to see every header explained.
- Check caching in the Cache lane.
Which Status Codes Are Related to 407?
- 401 Unauthorized: Authentication is missing or failed. Must send WWW-Authenticate. Really means "unauthenticated".
- 403 Forbidden: The server knows who you are and refuses anyway. Logging in again will not help.
- 502 Bad Gateway: A proxy or gateway got an invalid response from the upstream server.
Browse every code on the HTTP status codes page.
What Other Lanes Are in the Reference Section?
- HTTP status codes: Every IANA-registered status code, with a page per code.
- MIME types: File extensions to Content-Type, searchable both ways, plus a Content-Type parser.
- HTTP methods: GET, POST, PUT, PATCH, DELETE and the rest: safe, idempotent, cacheable.
Elsewhere in 2http: Header decoder, Cookie decoder, Cache-Control decoder, CORS checker, User-agent parser, and all eleven lanes on the 2http home page. Part of the 2suite.io privacy-first ecosystem.
Frequently Asked Questions
How do I give curl proxy credentials?
Use the --proxy-user option or include the user and password in the proxy URL. Keep real credentials out of shared scripts and shell history where possible.
Is HTTP 407 an error?
Yes. 407 is a client error response: the problem is in the request, so repeating it unchanged will usually fail again.
Is a 407 response cacheable by default?
No. Caches store a 407 only when Cache-Control or Expires explicitly allows it.
How Can You Verify That Nothing Leaves This Browser?
You do not have to take our word that your headers stay here. Developer tools show every request a page makes, so you can watch this page work and confirm that nothing is sent. The check takes under a minute.
- Open your browser developer tools with
F12, orCmd+Option+Ion a Mac, and select the Network tab. - Reload the page and let it finish. You will see the page's own files, its web fonts, and one anonymous page-view request. Nothing has been typed yet, so none of them can contain your headers.
- Click the clear icon in the Network tab so that the log is empty.
- Paste real headers into any lane and read the result.
- Look at the Network tab again. It is still empty. For extra proof, turn on offline mode after the page loads and every lane keeps working.
Only two things can add a line to that log, and neither carries your headers. Submitting the feedback form sends the vote and comment you typed. Typing characters in a script the page has not displayed yet, such as Cyrillic or Greek, can make the browser fetch the matching font file, and that request names only the font.
2http never sends a request on your behalf: the request builder writes code for you to run, and the meta inspector reads source you paste instead of fetching a URL. The production site also sends a Content-Security-Policy header that tells your browser to refuse connections to anywhere except this site and the anonymous analytics endpoint.