Using proxies is a great way to access websites and services that might otherwise restrict or block your requests. However, proxies can sometimes run into errors that prevent your requests from going through. In this comprehensive guide, I‘ll walk through the most common proxy error codes, explain what they mean, and provide actionable tips to resolve them. With this knowledge, you‘ll be equipped to quickly diagnose and fix proxy issues so you can get back to productive scraping and data extraction.
What is a Proxy Error Code?
A proxy error code is an HTTP status code that indicates there was a problem fulfilling the request sent via the proxy server. These codes are standardized across the web and offer insight into exactly where things went wrong.
There are five main classes of HTTP status codes:
- 1xx Informational
- 2xx Success
- 3xx Redirection
- 4xx Client Error
- 5xx Server Error
The first digit defines the class, while the second and third digits provide a more specific error code. For example, 403 means it‘s a 4xx client error, specifically 403 Forbidden.
While 1xx and 2xx codes mean things are working smoothly, 3xx, 4xx, and 5xx suggest something went wrong and action is required to resolve it. In this guide, we‘ll focus on the error codes – the ones starting with 3, 4, and 5. Recognizing these codes is the first step in diagnosing and addressing proxy problems.
301 – Moved Permanently
The 301 Moved Permanently status code indicates the resource you requested has been permanently relocated to a new URL. The proper URL will be specified in the Location response header.
How to Fix
- Update any bookmarks or stored URLs to use the new location
- Make future requests directly to the new URL instead of the old one
- Many scrapers and browsers will automatically follow the redirect, so no action may be necessary
This is usually not a serious error, since the data still exists at the new location. Just update your systems to request the new URL going forward.
305 – Use Proxy
The 305 Use Proxy code tells the client to use a proxy to access the requested resource. This has been deprecated due to security concerns, so it‘s rarely seen today.
How to Fix
- Connect through a proxy server and resend the request
- Consider using a proxy service like BrightData if you don‘t already have one configured
Since this code is outdated and unusual, double check that using a proxy is absolutely required and not just an incorrect response.
306 – Switch Proxy
The 306 Switch Proxy code indicates the client is already using a proxy, but should switch to a different one to send the request. Like 305, this has also been deprecated.
How to Fix
- Connect through a different proxy server and retry the request
- Rotate proxy IPs if using a pool of proxies
As with 305 codes, first validate that switching proxies is truly necessary today. If so, choose a new proxy and retry.
307 – Temporary Redirect
The 307 Temporary Redirect status code indicates the resource is temporarily available at a different URL. The Location response header specifies the temporary URL.
How to Fix
- Follow the temporary redirect URL provided
- Resend your request to the new temporary URL
- Handle 307 codes same as 301 codes, but use temporary URLs
This is similar to a 301 permanent redirect, except you should continue using the temporary URL only until it redirects back to the original.
400 – Bad Request
A 400 Bad Request error indicates there was a problem with the structure, syntax, or headers in the request. The server couldn‘t understand and process it.
How to Fix
- Double check the request for any invalid formatting, syntax errors, or missing headers
- Verify the request matches the API specification if accessing an API
- Retry the request after correcting any detected issues
Carefully inspect your request to find and fix the specific problem preventing the server from parsing it correctly.
401 – Unauthorized
The 401 Unauthorized status code indicates the request requires user authentication. The credentials provided were missing or incorrect.
How to Fix
- Provide proper authentication credentials if they weren‘t supplied originally
- If already providing credentials, double check they are correct
- Consider if the resource you‘re accessing requires authentication and if so, obtain proper approval
Note that scraping or accessing resources protected by authentication without permission may be unethical or illegal. Proceed with caution.
403 – Forbidden
A 403 Forbidden code means the request was valid, but the server refuses to authorize it. Access to the specified resource is completely forbidden for some reason.
How to Fix
- Verify you have permission to access the resource if authentication is required
- Try an alternative IP if the current one is blocked from the site
- Check for IP, rate limiting that may be preventing access
- The generic 403 error can be tricky to resolve. Work through possible permission issues methodically.
Since 403 codes are generic forbidden errors, the specific cause can vary. Slowly eliminate potential access restriction causes until the request succeeds.
404 – Not Found
The 404 Not Found code indicates the resource requested could not be found at the specified URL. The URL may be incorrect, the resource may have moved, or it may have been deleted entirely.
How to Fix
- Double check for any typos or errors in the requested URL
- See if the content was intentionally removed or relocated by the host
- Try accessing a cached version of the page from a web archive
- The resource may simply no longer exist at that URL
Carefully verify the URL is exactly as intended. If so, the content was likely removed intentionally by the host.
407 – Proxy Authentication Required
The 407 Proxy Authentication Required status indicates the client must provide authentication credentials to access the proxy server. This can happen when your proxy credentials are incorrect or missing.
How to Fix
- Provide valid username and password credentials for your proxy service
- Verify your IP address is whitelisted if required by your proxy provider
- Check for mismatches between client and proxy server configuration
Double check your proxy credentials and IPs are properly authorized. Contact your proxy provider for troubleshooting help if needed.
408 – Request Timeout
A 408 Request Timeout code means the server dropped the request because the client took too long to send the full request.
How to Fix
- Check for connectivity issues or bottlenecks that may be slowing the request
- Set longer timeout limits if timeouts are being triggered too aggressively
- Verify the server is not overloaded and unable to process requests quickly
- Retry the request under better network conditions
The timeout could be caused by client issues like a poor connection or server problems like overloading. Review the full path for delays.
429 – Too Many Requests
The 429 Too Many Requests status indicates rate limiting is in effect. The client made too many requests too quickly and has been throttled.
How to Fix
- Implement exponential backoff when throttling is detected
- Limit request rates to avoid crossing thresholds
- Use services like proxy rotation to spread requests across multiple IPs
- Respect required pacing between requests if thresholds are known
Rate limiting is common today. Implement smart pacing and throttling avoidance practices.
502 – Bad Gateway
A 502 Bad Gateway error means an intermediate proxy server received an invalid response from upstream servers attempting to fulfill the request.
How to Fix
- Retry the request after a delay in case of a temporary issue
- Check for network disruptions or downtime among the upstream servers
- If using multiple proxy servers, try switching to determine if one proxy works
- Exclude faulty proxy servers until the issue is resolved
Since this error comes from an intermediate proxy, see if bypassing or replacing that proxy resolves the problem.
503 – Service Unavailable
The 503 Service Unavailable status indicates the server is currently unable to handle the request due to temporary overload or maintenance.
How to Fix
- Retry the request after a delay in case the outage was temporary
- Check if the server is down for scheduled maintenance
- Try alternative servers/IPs not experiencing the outage
- Respect any Retry-After headers providing guidance on when to retry
Issues like planned maintenance or unexpected overloads can trigger 503 errors. Simply wait it out before retrying.
Conclusion
Troubleshooting proxy errors comes down to recognizing status codes, understanding their meanings, and applying the right solution for each. While retrying requests and adjusting proxies/IPs can resolve some codes, others require inspecting server configurations or request structures. With the descriptions and fixes above, however, you should now be armed to debug and resolve the most common proxy error codes.
For even more proxy knowledge, check out our in-depth guide on choosing the right proxies for web scraping. And contact us if you need help integrating reliable, high-performance proxies into your own scraping and data extraction projects. Our team has the proven experience to customize an optimal proxy solution for your specific needs.
What are the main causes of proxy errors?
The two primary causes are client-side misconfigurations like incorrect proxy settings or credentials, and server-side issues like overload or access restrictions. The specific error code provides more insight.
How can I debug and fix proxy errors quickly?
Carefully inspect the error code, validate proxy configurations and permissions, confirm URLs are correct, retry at intervals, switch proxy IPs/servers, and eliminate possible connection issues. Most errors can be resolved through one of those steps.
