407 Proxy Authentication Required Error

What the error means

The 407 code is sent by the proxy server itself, not by the site. It means the proxy requires authentication and either did not get it or got wrong credentials. Until you are authenticated, no request goes past the proxy.

In Prokso the code comes with a reason name in capital letters, for example 407 NO_USER or 407 TRAFFIC_EXHAUSTED. It shows what exactly is wrong: the credentials, the remaining traffic, the number of connections or the port.

Causes

• A typo in the username or password. An extra space, the username and password swapped, or a line cut off while copying.
• The password was changed. After a plan password reset, the old one stops working at once.
• The geo parameters are written incorrectly. The country and other parameters go in the username after “__” with no spaces; one extra character breaks the whole username.
• The program does not send the username and password. Some programs and extensions only understand the host:port format and silently drop the credentials.
• The plan has run out of traffic or is paused. In that case you get TRAFFIC_EXHAUSTED or USER_BLOCKED instead of NO_USER.
• Too many simultaneous connections. The THREADS_EXHAUSTED code: the program opened more threads than the plan allows.

How to fix it

1. Open the plan in the dashboard and copy the proxy line again — the whole line, using the copy button.
2. Check the format the program expects. If it needs the parts in a different order, convert the line in the proxy format converter.
3. Make sure the port is correct: 823 is HTTP, 824 is SOCKS5, 10000 to 20000 is a sticky IP.
4. Check the remaining traffic and the plan status. If the gigabytes have run out, top up traffic; if the plan is paused, resume it.
5. If the program cannot send a username and password, turn on the IP whitelist in the plan settings and add your address.
6. On THREADS_EXHAUSTED, reduce the number of threads or split the tasks between plans.

How to check that it works

Paste the line into the proxy checker: it shows whether the proxy accepts your credentials and which country it exits from. If the check passes but the program still returns 407, the cause is in the program settings.