Quick steps to fix HTTP 407 proxy authentication

• Confirm proxy details. Ask your IT team or check your VPN/proxy portal for the correct proxy host, port, and protocol (HTTP or HTTPS).
• Verify your username and password. If your company uses domain accounts, use domainusername or username@domain.
• Set system proxy settings. Configure Windows, macOS, or Linux so all apps see the proxy.
• Clear old credentials. Remove saved passwords that might be wrong.
• Test with curl. Make a quick request through the proxy with a known good site.
• Restart your app or browser. Many tools read proxy settings only at launch.
• Bypass internal hosts. Set NO_PROXY for localhost and your intranet.

Understand what triggers a 407

Typical reasons you see it

• Wrong username or password, or expired password.
• Incorrect proxy host, port, or protocol.
• PAC script (auto proxy) points to a dead or wrong proxy.
• Your app does not use the system proxy, so it never sends credentials.
• Proxy needs NTLM or Kerberos and you sent Basic auth.
• Special characters in your password were not URL encoded.

Set your system proxy the right way

Windows 10/11

• Go to Settings > Network & Internet > Proxy.
• If your company uses a script, turn on “Use setup script” and enter the script URL (PAC).
• If you need manual settings, turn on “Use a proxy server,” then enter address and port.
• Open Internet Options > Connections > LAN settings to confirm the same values.
• Open Credential Manager and delete wrong saved credentials for the proxy.
• WinHTTP (for services) can be set with:
  netsh winhttp show proxy
  netsh winhttp reset proxy
  netsh winhttp set proxy proxy-server=”http=host:port;https=host:port”
• For command-line tools, set environment variables:
  setx http_proxy http://user:pass@host:port
  setx https_proxy http://user:pass@host:port

macOS

• Open System Settings > Network. Select your active network (Wi‑Fi or Ethernet).
• Click Details > Proxies. Check “Web Proxy (HTTP)” and “Secure Web Proxy (HTTPS).” Enter host, port, and credentials.
• If you use a PAC file, check “Automatic Proxy Configuration” and enter the script URL.
• Remove stale passwords from Keychain Access for the proxy host.
• For terminal apps:
  export http_proxy=”http://user:pass@host:port”
  export https_proxy=”http://user:pass@host:port”
  export NO_PROXY=”localhost,127.0.0.1,.intranet.local”

Linux

• Desktop: Settings > Network > Network Proxy. Set Manual or Automatic (PAC).
• Shell:
  export http_proxy=”http://user:pass@host:port”
  export https_proxy=”http://user:pass@host:port”
  export NO_PROXY=”localhost,127.0.0.1,::1,.corp.local,10.0.0.0/8″
• APT example (Debian/Ubuntu) in /etc/apt/apt.conf.d/99proxy:
  Acquire::http::Proxy “http://user:pass@host:port/”;
  Acquire::https::Proxy “http://user:pass@host:port/”;
• Encode special characters in credentials. Example: @ becomes %40, : becomes %3A.
• Use these steps to fix HTTP 407 proxy authentication on Linux when command-line tools fail.

Configure popular tools and browsers

Browsers

• Chrome and Edge use system proxy by default. Set it at the OS level and restart the browser.
• Firefox: go to Settings > General > Network Settings. Choose “Use system proxy settings” or set “Manual proxy configuration.” Clear any saved logins and try again.

Git

• Set proxy:
  git config –global http.proxy “http://user:pass@host:port”
  git config –global https.proxy “http://user:pass@host:port”
• If your proxy uses Basic:
  git config –global http.proxyAuthMethod basic
• Remove proxy:
  git config –global –unset http.proxy
  git config –global –unset https.proxy

Node.js, npm, and yarn

• Environment variables often work best:
  export HTTP_PROXY=”http://user:pass@host:port”
  export HTTPS_PROXY=”http://user:pass@host:port”
• npm config:
  npm config set proxy “http://user:pass@host:port”
  npm config set https-proxy “http://user:pass@host:port”
• yarn config:
  yarn config set proxy “http://user:pass@host:port”
  yarn config set https-proxy “http://user:pass@host:port”

Python and pip

• Environment variables:
  export PIP_PROXY=”http://user:pass@host:port”
  (or rely on http_proxy/https_proxy)
• pip config:
  Linux/macOS: ~/.config/pip/pip.conf
  Windows: %APPDATA%pippip.ini
  Content:
  [global]
  proxy = http://user:pass@host:port
• requests library example:
  proxies = {“http”: “http://user:pass@host:port”, “https”: “http://user:pass@host:port”}
  requests.get(“https://example.com”, proxies=proxies)

Docker

• For Docker Engine (systemd):
  Create /etc/systemd/system/docker.service.d/http-proxy.conf with:
  [Service]
  Environment=”HTTP_PROXY=http://host:port” “HTTPS_PROXY=http://host:port” “NO_PROXY=localhost,127.0.0.1,.corp.local”
  Then run: systemctl daemon-reload && systemctl restart docker
• For builds, set BuildKit proxy or pass build-args:
  docker build –build-arg http_proxy=… –build-arg https_proxy=… .

Handle special corporate setups

• NTLM or Kerberos SSO: Use domainusername in your credentials. For curl, try:
  curl -v –proxy http://host:port –proxy-ntlm –proxy-user “domainuser:pass” https://example.com
• PAC files: If you use a PAC script, make sure the URL is reachable and correct. Load it in a browser to verify it returns JavaScript.
• Split tunneling and bypasses: Add intranet domains and IP ranges to NO_PROXY so local traffic does not hit the proxy.
• Account lockouts: Too many bad attempts can lock your account. Reset your password or wait per company rules.
• Protocol mismatch: If the proxy requires HTTPS, do not set an HTTP proxy URL. Match the protocol your IT team provides.

Test and confirm the fix

Quick curl checks

• Basic test:
  curl -I -x http://host:port https://example.com
  If you get 407, add credentials:
  curl -I -x http://host:port -U user:pass https://example.com
• Verbose output:
  curl -v –proxy http://host:port –proxy-user user:pass https://api.github.com
  Look for Proxy-Authenticate and Proxy-Authorization headers. A 200/301/302 means it worked.

Validate in your app

• Restart the app after changing proxy settings.
• Check if the app has its own proxy setting that overrides the system.
• Try a direct connection (disable proxy) to confirm the issue is only the proxy.

Security tips when using proxies

• Do not share your proxy password in screenshots or logs.
• Use a machine-level secret store or credential manager when possible.
• Prefer environment variables over hardcoding credentials in scripts.
• URL-encode special characters in usernames and passwords to avoid parsing errors.

When to call IT

• You have the right settings, but 407 persists across devices.
• Your account is locked or your password does not work anywhere else.
• The proxy PAC file URL fails to load, or the proxy host does not resolve.
• You need NTLM/Kerberos single sign-on and your tools do not support it natively.

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