---
title: "Website Error Codes: Types, Fixes and SEO Risk Guide"
description: "Website error codes guide status types, causes, fixes, prevention, SEO impact, 404 pages, 500 errors, redirects, and checking tools."
date: 2026-05-04
type: post
url: /website-error-code
canonical: https://webmaintenance.com.au/website-error-code
---

# Website Error Codes: Types, Fixes and SEO Risk Guide

*Website error codes guide status types, causes, fixes, prevention, SEO impact, 404 pages, 500 errors, redirects, and checking tools.*

Website error codes identify whether a page request succeeded, redirected, failed, or reached the wrong source, then connect each HTTP status code to a cause, diagnostic tool, prevention check, repair action, SEO handling decision, monitoring routine, and accountable owner for follow-up.




The article explains status-code classes, common web page failures, likely causes, checking tools, prevention routines, troubleshooting sequences, search impact, 404 ranking risk, 500 server faults, redirect selection, custom 404 pages, and non-server error sources.





## What is HTTP protocol and what do status codes mean?



HTTP protocol defines how a browser requests a web resource from a server, and HTTP status codes are three-digit server responses that describe whether that request succeeded, redirected, failed because of the request, or failed because of the server during delivery. The request can target a URL, image, script, form action, API endpoint, or downloadable file. The response value gives the browser, crawler, and site owner a shared diagnostic signal.



HTTP status codes are grouped into five categories based on the type of response:



- **1xx informational responses** confirm that the server received the browser request and continues processing it.
- **2xx successful responses** confirm that the request reached the server and produced the expected result.
- **3xx redirection messages** send the client to another URL or resource location.
- **4xx client error responses** show that the request, URL, permission, or browser-side input created the failure.
- **5xx server error responses** show that the server, gateway, application, or hosting layer failed during processing.



![HTTP status codes type](https://webmaintenance.com.au/assets/images/website-error-code/type_of_http_status_code.webp)



## What are the different types of HTTP status codes (1xx-5xx)?



HTTP status codes are three-digit response numbers grouped into five classes, from 1xx through 5xx, that identify informational responses, successful requests, redirection messages, client errors, and server errors during client-server communication, troubleshooting, and site diagnostics. Each class gives a different action signal. Successful and informational responses usually confirm normal delivery, while redirection, client error, and server error classes often require URL, access, hosting, or application review.



The five types of HTTP status codes are summarised in the table below.




 
| Code Range | Meaning | Example | Owner Action |
| --- | --- | --- | --- |
| 1xx | Informational response: the request is received and processing continues. | 100 Continue | No action unless requests stall. |
| 2xx | Successful request: the server accepted, processed, or returned the requested resource. | 200 OK | No error action. Monitor normal page delivery. |
| 3xx | Redirection message: the requested resource moved or requires another URL. | 301 Moved Permanently | Check destination relevance, redirect chains, and index signals. |
| 4xx | Client error: the URL, permission, request syntax, or browser-side input created a failure. | 404 Not Found | Fix broken links, permissions, forms, or high-value missing URLs. |
| 5xx | Server error: the server, gateway, or application failed during request handling. | 500 Internal Server Error | Check hosting, logs, application faults, and uptime impact. |






## What are the most common website error codes and their meanings?



Common website error codes connect a failed request to a status value, meaning, source category, and likely cause, with 404 Not Found, 500 Internal Server Error, and 403 Forbidden appearing before less frequent gateway and availability errors in site audits. Client-side errors are 4xx responses caused by request, URL, permission, authentication, or browser-side conditions. Server-side errors are 5xx responses caused by application, gateway, hosting, or resource failures.



The most common website error codes encountered by users are listed below.



1. **404 Not Found:** the requested URL has no matching resource. Common causes include deleted pages, changed slugs, broken internal links, and mistyped URLs.
2. **500 Internal Server Error:** the server hit an unexpected condition. Common causes include application exceptions, PHP errors, file permission faults, and plugin conflicts.
3. **403 Forbidden:** the server understood the request but blocked access. Common causes include permission rules, security filters, IP blocks, and directory restrictions.
4. **400 Bad Request:** the server rejected the request syntax. Common causes include malformed URLs, invalid cookies, oversized headers, and broken form submissions.
5. **401 Unauthorized:** the requested resource requires authentication. Common causes include missing login credentials, expired sessions, and protected admin areas.
6. **502 Bad Gateway:** an upstream server returned an invalid response. Common causes include reverse proxy faults, CDN issues, API downtime, and gateway configuration errors.
7. **503 Service Unavailable:** the server lacks temporary capacity. Common causes include maintenance mode, traffic spikes, hosting limits, and overloaded application resources.
8. **504 Gateway Timeout:** a gateway waited too long for an upstream response. Common causes include slow APIs, database latency, server overload, and network routing faults.





## What causes website errors?



Website errors come from code faults, hosting failures, DNS records, browser cache, network conditions, plugins, CDN rules, SSL certificates, security filters, or incorrect URLs because every page request passes through multiple technical layers before rendering content to users. The cause determines the repair owner. A visitor can test cache or network conditions, while a site owner, developer, host, DNS provider, or CDN provider controls deeper fixes.



- Poor or incorrect coding creates broken templates, invalid scripts, application exceptions, and malformed responses.
- Server connection failure or hosting downtime blocks access to pages, files, databases, or upstream services.
- DNS problems or expired domain settings send requests to the wrong destination or no destination.
- Browser cache or compatibility issues display outdated files, blocked scripts, or device-specific failures.
- Malware, outdated plugins, or security conflicts trigger redirects, forbidden responses, form errors, and suspicious file changes.



The main website error sources are compared below.




 
| Error Source | What It Affects | First Check |
| --- | --- | --- |
| Server or hosting | 5xx errors, downtime, slow responses, unavailable files, database failures. | Hosting status, resource limits, web server logs, application logs. |
| Browser or device | Cached pages, blocked scripts, display faults, cookie-related errors. | Private window, another browser, cache purge, device comparison. |
| DNS or domain | Site unavailable for some users, wrong server destination, expired domain signals. | DNS records, nameservers, domain expiry, propagation state. |
| Network or ISP | Local access failures, intermittent loading, region-specific availability issues. | Another network, mobile hotspot, external uptime checker. |
| Plugin, theme, or CMS | Broken templates, 500 errors, form faults, redirect loops, JavaScript failures. | Recent updates, conflict testing, CMS error logs, staging rollback. |
| CDN, firewall, or SSL | 403 errors, 502 errors, mixed content, certificate warnings, blocked assets. | CDN logs, WAF rules, SSL certificate, cache rules, origin connection. |






## How to check for website errors and what tools to use?



Website errors are checked by testing pages, links, code, performance, indexing, security, browser console messages, and server responses with diagnostic tools that identify broken links, HTML faults, crawl blocks, JavaScript errors, malware warnings, redirect issues, and availability failures. A single check rarely covers every layer. A complete review combines crawler data, browser data, search data, performance data, uptime data, and security data.



1. Crawl the website for broken links, missing pages, redirect chains, and soft 404 patterns.
2. Check browser developer tools for console errors, blocked scripts, failed network requests, and HTTP response values.
3. Validate HTML, CSS, accessibility, structured data, and mobile rendering issues.
4. Test speed, mobile usability, Core Web Vitals, resource loading, and response time.
5. Inspect indexing, crawl errors, sitemap coverage, and URL status in Google Search Console.
6. Scan for malware, SSL certificate errors, mixed content, security warnings, and unexpected redirects.



Use each tool for a specific diagnostic job rather than running disconnected checks.




 
| Tool | What It Checks | Best Output |
| --- | --- | --- |
| Google Search Console URL Inspection Tool | Indexing status, crawl errors, canonical signals, sitemap discovery, and page availability. | Indexing reason, crawl result, selected canonical, last crawl date. |
| Browser developer tools | Console errors, network failures, HTTP response codes, blocked resources, cookies, and caching behaviour. | Failed request URL, response status, JavaScript error, blocked asset. |
| Google Lighthouse | Performance, accessibility, SEO checks, Core Web Vitals signals, and mobile rendering issues. | Performance score, accessibility issue, SEO warning, render-blocking resource. |
| HTML validation tools | Broken markup, missing attributes, invalid nesting, and document structure errors. | Line-level markup issue and validation warning. |
| Website crawlers | Broken links, redirect chains, missing titles, status codes, orphan pages, and internal linking faults. | URL list grouped by 3xx, 4xx, 5xx, redirect chain, and source link. |
| Uptime monitor | Availability, 5xx responses, SSL expiry, response time, region-specific downtime. | Incident timestamp, affected endpoint, response code, alert history. |
| Security scanner | Malware, SSL issues, mixed content, suspicious redirects, vulnerable files, and blacklist warnings. | Security warning type, affected URL, suspicious file, certificate issue. |






## How to prevent website errors?



Website errors are prevented through recurring maintenance, pre-publish testing, uptime monitoring, software updates, backups, SSL checks, and security scans because these controls reduce broken links, compatibility faults, expired settings, malware changes, server-side incidents, and release defects. Prevention works best as a schedule. The schedule connects each technical layer to a repeatable test before users or search engines encounter the fault.



The main ways to prevent website errors are listed below.



1. Keep website software, plugins, themes, CMS core files, and server packages updated.
2. Back up the website before major changes, plugin updates, database edits, and hosting migrations.
3. Monitor uptime, SSL certificates, DNS resolution, server performance, and response codes.
4. Test forms, links, checkout flows, search functions, redirects, and key landing pages regularly.
5. Use secure coding practices, strong passwords, malware scans, least-privilege access, and firewall rules.
6. Check mobile responsiveness, browser compatibility, page speed, Core Web Vitals, and script loading after releases.



![Website error prevention](https://webmaintenance.com.au/assets/images/website-error-code/website_error_prevention.webp)


The prevention cadence below turns general checks into a repeatable maintenance routine.




 
| Cadence | Prevention Check | Purpose |
| --- | --- | --- |
| Before major changes | Create a backup and record the current working version. | Restore the site if an update, edit, or migration creates an error. |
| After every deployment | Test key pages, forms, checkout, redirects, scripts, and mobile rendering. | Catch broken functions before users or crawlers encounter them. |
| Daily | Monitor uptime, SSL status, 5xx responses, and response time. | Detect outages, certificate faults, and server-side incidents quickly. |
| Weekly | Run a technical crawl for broken links, 404 pages, redirect chains, and missing assets. | Find internal URL problems and crawl waste before they expand. |
| Monthly | Review Google Search Console coverage, crawl stats, and page indexing issues. | Identify SEO-impacting errors, excluded URLs, and recurring server response patterns. |
| After plugin or CMS updates | Check templates, forms, JavaScript, payment steps, and admin functions. | Detect compatibility issues from extensions, themes, modules, and core patches. |






## How to fix and troubleshoot website error codes?



Website error codes are fixed by identifying the exact browser message, classifying the fault source, checking the likely technical cause, applying the repair, purging affected caches, and retesting the same URL across devices, tools, logs, and monitoring systems. This order prevents random fixes. It also separates visitor-side checks from site-owner, developer, hosting, DNS, and CDN responsibilities.



The main steps to troubleshoot website error codes are listed below.



1. Check the exact error code, affected URL, browser message, timestamp, and device context.
2. Refresh the page, clear cache, test private browsing, and compare another browser or device.
3. Check server status, hosting account health, domain expiry, resource limits, and recent deployments.
4. Review DNS records, SSL certificate status, CDN settings, redirect rules, and firewall blocks.
5. Check website error logs, browser developer tools, application logs, plugin logs, and failed network requests.
6. Fix the root cause, purge cache, retest the affected page, and monitor the same URL after release.



The fix owner depends on where the failed request occurs.




 
| Fix Owner | Typical Error Area | Action |
| --- | --- | --- |
| Visitor | Browser cache, cookies, local device, local network. | Refresh, clear cache, test private browsing, try another browser or network. |
| Site owner | CMS, plugins, redirects, page deletions, forms, content changes. | Check admin changes, plugin conflicts, broken links, redirects, and page status. |
| Developer | Application code, templates, JavaScript, APIs, database queries. | Review logs, reproduce the fault, patch code, test staging, deploy fix. |
| Hosting provider | Server resources, web server configuration, database service, outages. | Check server status, resource limits, file permissions, PHP version, and incident logs. |
| DNS or CDN provider | Nameservers, DNS records, CDN cache, firewall, proxy, SSL edge issues. | Review DNS records, CDN rules, origin connection, WAF blocks, and certificate status. |





For 500 Internal Server Error diagnostics, follow this order:



1. Record the timestamp, affected URL, browser message, and recent deployment or update.
2. Check application logs, server logs, PHP error logs, and database connection errors.
3. Review file permissions, server rules, plugin conflicts, theme errors, and PHP memory limits.
4. Check hosting resource limits, disk usage, CPU spikes, database health, and provider incident status.
5. Roll back the last change on staging or production, purge cache, then retest the same URL.





## How do error codes affect SEO and how to handle them?



Website error codes affect SEO by telling search engines whether a page is crawlable, indexable, redirected, removed, blocked, unavailable, temporarily failing, or wasting crawl activity because of a server response, client error, redirect rule, or access condition. Search impact depends on URL value and recurrence. A single low-value 404 differs from an indexed landing page with backlinks, while repeated 5xx errors block crawler access to live content.



The main SEO effects of website error codes and how to handle them are listed below.



- Fix important 404 errors by restoring the page or adding a relevant 301 redirect when the URL has backlinks, organic traffic, conversions, indexation, or internal links.
- Leave low-value 404 URLs in place when the page is intentionally removed and no relevant replacement exists.
- Resolve 5xx server errors quickly so search engines regain access to pages, scripts, images, and sitemap URLs.
- Use 301 redirects for moved pages to preserve link equity, canonical signals, and destination clarity.
- Use 302 redirects only for temporary campaigns, tests, short maintenance routes, or temporary page swaps.
- Monitor crawl errors in Google Search Console to identify indexing issues, redirect faults, and recurring unavailable URLs.
- Remove or noindex pages only when they belong outside search results and no replacement URL exists.




### Do 404 errors hurt your SEO rankings?



NO, 404 errors do not usually hurt SEO rankings directly unless they affect important indexed pages, backlinks, crawl efficiency, or user experience, because low-value missing URLs differ from deleted URLs with organic traffic, internal links, external links, or conversions today. See our [**website down**](https://webmaintenance.com.au/website-down) guide for recovery steps when 404s cause availability issues.




### Can you fix a 500 server error yourself?



YES, site owners fix a 500 server error themselves when they control the website or hosting account because administrator access reveals error logs, file permissions, server configuration, plugin conflicts, PHP limits, database faults, and recent deployments quickly. Regular [**website backup**](https://webmaintenance.com.au/website-backup) ensures a clean restore point is available before troubleshooting begins.





### When do you use 301 or 302 redirects?



Use a 301 redirect for permanent URL changes and a 302 redirect for temporary changes because search engines treat permanent moves, merged pages, temporary campaigns, testing routes, maintenance destinations, and short-term page swaps differently for indexing and SEO value.




### Is a custom 404 page necessary?



YES, a custom 404 page improves user experience even though it does not fix the broken URL itself because clear messaging, a search bar, homepage links, popular page links, and broken-link tracking keep visitors inside the site safely.




### Are all website errors caused by your server?



NO, not all website errors come from your server; some come from the browser, DNS, network connection, plugins, CDN rules, [**website security**](https://webmaintenance.com.au/website-security) filters, SSL certificates, cache layers, or incorrect URLs, so source classification controls repair ownership clearly.




A complete [**website maintenance**](https://webmaintenance.com.au/) review links every page request to one server response, one source category, one troubleshooting action, one prevention cadence, and one SEO handling decision, so HTTP status codes, server response checks, Google Search Console signals, redirects, browser issues, and DNS errors stay traceable during recurring site audits.