In the digital landscape, HTTP errors are inevitable. They serve as signals that something has gone awry between the user’s browser and a web server. These errors, while frustrating for users, also provide valuable information for website owners and developers to diagnose and resolve issues.
In this blog, we’ll break down the most common types of HTTP errors, their causes, and how to address them.
What Are HTTP Errors?
HTTP (HyperText Transfer Protocol) errors occur when a server cannot process a browser’s request correctly. Each error is assigned a status code, typically categorised into five classes:
1xx – Informational
Rarely seen by users, these indicate that a request is being processed.
2xx – Success
Everything is working as expected.
3xx – Redirection
The requested resource has moved or requires further action.
4xx – Client Errors
Issues on the user’s side, like broken links.
5xx – Server Errors
Problems on the server’s end, such as overloads or misconfigurations.
Common HTTP Errors & What They Mean
4xx Errors: Client-Side Issues
404 Not Found
Cause: The requested page does not exist, often due to broken links or mistyped URLs.
Fix:
- Check for typos in links.
- Implement 301 redirects for moved or deleted pages.
- Create a custom 404 page to guide users back to your site.
400 Bad Request
Cause: The server cannot process the request due to malformed syntax.
Fix:
- Clear browser cookies and cache.
- Ensure URLs are encoded correctly.
- Debug client-side scripts causing the error.
401 Unauthorized
Cause: Authentication is required, but credentials are missing or incorrect.
Fix:
- Confirm correct login details.
- Check the configuration of authentication systems like OAuth or API keys.
403 Forbidden
Cause: The server understands the request but refuses to fulfil it.
Fix:
- Verify user permissions.
- Ensure directory or file permissions are configured correctly.
429 Too Many Requests
Cause: The user has sent too many requests in a given time frame, triggering rate limits.
Fix:
- Implement exponential backoff in API calls.
- Adjust rate limit policies on the server.
5xx Errors: Server-Side Issues
500 Internal Server Error
Cause: A generic error message indicating a server malfunction.
Fix:
- Check server logs for detailed error messages.
- Debug application code or server configurations.
502 Bad Gateway
Cause: The server acting as a gateway received an invalid response from an upstream server.
Fix:
- Restart servers or proxy services.
- Check firewall or load balancer configurations.
503 Service Unavailable
Cause: The server is temporarily overloaded or down for maintenance.
Fix:
- Scale server resources during high traffic.
- Display a maintenance message with an expected resolution time.
504 Gateway Timeout
Cause: The server acting as a gateway timed out waiting for a response.
Fix:
- Optimise upstream server performance.
- Adjust timeout settings in proxy configurations.
Less Common but Notable HTTP Errors
408 Request Timeout
Cause: The client took too long to send a request.
Fix:
- Improve connection speed or reduce server timeout thresholds.
410 Gone
Cause: The requested resource is permanently removed.
Fix:
- Use 301 redirects for alternative content.
- Inform users why the content is no longer available.
418 I’m a Teapot
Cause: A playful error defined in the 1998 April Fools’ RFC 2324 as an Easter egg.
Fix: Just enjoy the joke!
Why Understanding HTTP Errors Matters
For website owners, understanding and addressing HTTP errors is essential to maintaining a positive user experience and good SEO. Errors like 404s and 503s can frustrate users and lead to increased bounce rates, while unresolved server-side issues can harm your website’s search rankings.
Tools to Monitor and Fix HTTP Errors
Google Search Console: Identifies crawl errors like 404s.
Pingdom or Uptime Robot: Monitors server uptime and detects 5xx errors.
Browser Developer Tools: Helps debug client-side issues causing 4xx errors.
Server Logs: Provides detailed insights into server errors.
Proactive Steps to Prevent HTTP Errors
Regular Maintenance: Monitor and update your website’s plugins, themes, and code.
Broken Link Checks: Use tools like Screaming Frog or Ahrefs to identify and fix broken links.
Scalable Hosting: Choose a hosting plan that can handle traffic spikes.
Custom Error Pages: Create helpful error pages to minimise user frustration and direct them back to your site.
