Proxy Error Codes: A Troubleshooting Sheet for Teams
A failed request through a proxy comes back with a status code, and that code tells you two things: what went wrong, and whose job it is to fix it. Authentication and connectivity problems point to your own setup; permission and rate-limit codes come from the target site. Telling them apart quickly saves guesswork, and it saves raising support tickets that turn out to be unnecessary.
Below are the codes teams meet most often through a proxy, each with a practical first fix. For a live check, our proxy checker confirms whether a proxy authenticates and shows its exit IP.
We write these guides for e-commerce, marketing and agency teams that pay for proxies by the gigabyte.
Errors on your side of the connection
407 Proxy Authentication Required
The proxy did not accept the credentials it was sent. Re-enter the username and password or, if your team authenticates by IP, make sure the server's current IP is on the whitelist. This is the error new team members hit most often while setting up.
Connection refused / timeout
The request never got as far as the gateway. Check the host and port, confirm that the protocol you selected (HTTP/HTTPS or SOCKS5) is the one the endpoint expects, and make sure a local firewall is not stopping the connection.
Errors returned by the target site
403 Forbidden
The target declined to serve the request, commonly because of IP reputation or its own rules. For protected sites, move to a higher-trust residential IP, and double-check that the work falls within the site's terms.
429 Too Many Requests
A rate limit has been reached. Reduce the pace, add randomised delays, lower concurrency and use rotation to spread requests across more IPs. Teams scaling up a project see this code more than any other.
502 / 503 / 504
Bad gateway, service unavailable and gateway timeout generally signal a temporary fault at the target or further upstream. Retry with exponential backoff; if the errors keep coming, the target itself may be down.
Quick reference for the team
Pin this table where everyone on the team can see it: the common codes, what usually causes them and the first fix to try.
| Code | Meaning | Likely cause | First fix |
|---|---|---|---|
| 407 | Proxy auth required | Rejected credentials or unlisted IP | Re-enter credentials; update whitelist |
| 403 | Forbidden | IP reputation or the site’s rules | Higher-trust pool; review the terms |
| 429 | Too many requests | Rate limit reached | Lower pace and concurrency; rotate |
| 502/504 | Gateway error | Temporary target/upstream issue | Retry with exponential backoff |
| Timeout | No response | Connectivity or wrong host/port | Check host, port and protocol |
A troubleshooting order everyone can follow
Work from your own setup outwards when something fails:
- Test the proxy itself in the proxy checker. A pass rules out authentication and connectivity problems (407, timeouts).
- Seeing 429? Look at pacing: lower the rate and concurrency, and add rotation.
- Seeing 403 on a protected site? Look at the pool, and move to residential or premium.
- Seeing 5xx? Retry with backoff before treating it as a real fault.
Whatever the code, collect only publicly available data within each site's terms of service, and accept that no proxy can promise access. If a proxy still fails after these checks, open a ticket from the dashboard and our 24/7 support team will look into it.
Plans and further reading
Whichever type your team orders, you get HTTP/HTTPS and SOCKS5, a choice of username/password or IP-whitelist authentication, 55+ countries and 99.9% uptime. Compare tiers on the pricing page or buy proxies, and read why proxies get blocked for a closer look at 403 and 429.
Match the pool to the workflow
Every pool is billed per GB and run from the same dashboard, so one team can keep low-cost volume work and high-trust checks side by side.
High-volume collection from unprotected sites, automation, SEO tools
Market research, ad verification and geo-accurate checks on protected sites
Phone-first platforms, app and mobile ad testing
Hard targets where every failed request is costly
Covering several markets in one report? MIX packages combine multi-country residential traffic in a single order. Agencies buying on behalf of clients can apply for the reseller programme.
Get your team running
Per-GB pricing from $3.50 · 55+ countries · instant delivery · 30-day validity · no traffic logs · 24/7 human support
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1
Size the job
Pick a proxy type in the proxy calculator and enter the gigabytes you expect to use to see the order total.
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2
Order and pay
Choose the pool on the proxies page and pay by card through Stripe or in crypto through Cryptomus. Each order is billed per GB and does not renew on its own.
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3
Share access
Credentials appear in the dashboard as soon as payment clears. Add them to each tool with a login or an IP whitelist, then send one test request before the real job starts.
Questions team leads ask
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