Proxy timeout errors: the connection hangs, then gives up

Three timeout outputs we measured

We set up a test proxy that accepts TCP connections and never replies, then ran the same request with two kinds of time limit (address rewritten as 203.0.113.10:8080, user123:pass456):

• curl --connect-timeout 10 -x http://user123:[email protected]:8080 https://example.com gives curl: (28) Proxy CONNECT aborted due to timeout. That limit covers only the connection phase.
• Swapping in -m 10 (a limit on the whole transfer) gives curl: (28) Connection timed out after 10002 milliseconds.
• Chromium pointed at the same proxy reports ERR_TIMED_OUT; the proxy checker reports timeout.

Causes, most likely first

• Your network silently blocks the proxy port. Office, hotel and campus Wi-Fi often drop packets to unusual ports instead of refusing them, so you wait forever.
• The timeout in your code is too short. A proxy in a distant country needs a little longer for the handshake; a 2–3 second limit can cut off a proxy that works fine.
• The proxy or destination is overloaded. The proxy accepts the connection but waits on the website, and your patience runs out first.
• Wrong IP. A typo that lands on an unresponsive address produces silence rather than a refusal.

Fixes by environment

• Windows/Chrome: try the same proxy over your phone's mobile data. If the timeout disappears, the original network is blocking; read checking the proxy and the firewall.
• Antidetect browsers: the proxy check button usually has a fixed wait. Retry a few times, and if only some profiles fail, compare their proxy line with one that works.
• Telegram: being stuck on connecting after enabling a proxy is often a timeout too; test the proxy in the checker before changing Telegram.
• Python requests: pass timeout=(10, 30), meaning 10 seconds to connect and 30 seconds to read. Catch requests.exceptions.ConnectTimeout and requests.exceptions.ReadTimeout separately to see where it hangs, and add a few spaced retries rather than an unlimited timeout.
• curl: use --connect-timeout to measure the connection step alone and -m to cap the whole command.

Timeout or just slow?

A slow proxy still answers, only late. The proxy speed test shows real response times; if they sit close to your software's timeout, raise the limit or choose a proxy in a country closer to the target. If repeated tests never get an answer, it is a genuine timeout, and a ticket with the checker result is the next step.

Step by step

1. 1

   Confirm the timeout with the checker

   Paste the proxy line into the proxy checker. A timeout result means no reply arrived within the wait limit.

2. 2

   Switch networks to narrow it down

   Retry over mobile data. If it works, the original network or its firewall is the issue.

3. 3

   Measure response time

   Run the proxy speed test to see whether the proxy is slow or silent.

4. 4

   Tune timeouts and retries in your software

   Raise the connect limit to around 10 seconds, add retries, and run the task again.

Frequently asked questions