Understanding Crawl Errors
If you’re managing a website, one of the first things to pay attention to is how search engines like Google crawl and index your site. When something goes wrong during this process, its called a crawl error. These errors can hurt your website’s visibility in search results, which means fewer people finding your content online.
What Are Crawl Errors?
Crawl errors occur when a search engine tries to access a page on your site but can’t reach it successfully. These errors are usually reported in tools like Google Search Console and fall into two main categories: site errors and URL errors.
Types of Crawl Errors
| Error Type | Description |
|---|---|
| Site Errors | Affect your entire website and prevent Google from crawling it at all. Common causes include DNS issues, server errors, or robots.txt blocking. |
| URL Errors | Affect individual pages on your website. Examples include 404 Not Found, soft 404s, and access denied errors. |
Why Crawl Errors Matter for SEO
Crawl errors can stop search engines from accessing parts of your site. If important pages cant be crawled or indexed, they won’t show up in search results. This directly affects your sites organic traffic and overall SEO performance.
- Lowers Page Visibility: Pages with crawl errors may not appear in search results at all.
- Affects Site Authority: Broken links and inaccessible pages signal poor site maintenance, which can harm your ranking.
- Wastes Crawl Budget: Search engines have a limited number of pages theyll crawl each day. Errors can waste that budget on broken pages instead of valuable content.
How Search Engines Handle Crawl Errors
When Google encounters an error while crawling your site, it may try again later—but repeated issues can cause the page to be removed from the index over time. The faster you identify and fix these problems, the better chance your content has to stay visible in search results.
Quick Tip:
The easiest way to monitor crawl errors is through Google Search Console. It shows detailed reports about what went wrong and where so you can take action quickly.
2. Common Types of Crawl Errors
Understanding crawl errors is key to maintaining a healthy website and ensuring search engines can properly index your content. Let’s explore the most common types of crawl errors, what they mean, and why they happen.
404 Not Found
A 404 error occurs when a user or crawler tries to access a page that doesn’t exist on your site. This could be due to deleted pages, broken internal links, or incorrect URLs.
Causes:
- Page was removed or renamed without a redirect
- Typos in internal or external links
- Outdated sitemaps or backlinks pointing to non-existent pages
DNS Issues
Domain Name System (DNS) errors happen when crawlers cant connect to your domain. If Googlebot can’t resolve your DNS, it won’t be able to crawl your site at all.
Causes:
- Problems with your DNS provider
- Misconfigured DNS settings
- Temporary outages or network failures
Server Errors (5xx)
Server errors occur when your web server fails to respond properly to the crawlers request. These are typically temporary but should be monitored closely.
Common 5xx Errors:
| Error Code | Description |
|---|---|
| 500 | Internal Server Error – generic error when the server fails unexpectedly |
| 502 | Bad Gateway – invalid response from an upstream server |
| 503 | Service Unavailable – server is overloaded or down for maintenance |
| 504 | Gateway Timeout – server didn’t respond in time |
Blocked Resources
Crawlers need access to various resources like JavaScript, CSS, and images in order to render your pages correctly. When these are blocked by robots.txt or noindex tags, it can impact how your content is understood and ranked.
Causes:
- robots.txt disallow rules blocking important files or folders
- Noindex meta tags on critical pages or assets
- .htaccess rules preventing bot access unintentionally
Tackling these common crawl errors early helps improve your sites visibility and ensures that search engines can access and understand all of your content.
3. Identifying Crawl Issues Using Google Search Console
If youre managing a website, one of the most effective ways to detect and understand crawl errors is through Google Search Console (GSC). This free tool from Google gives you direct insights into how Googles bots interact with your site. Heres how you can use it to your advantage.
Accessing the Right Reports
Once youve verified your website in GSC, head over to two key sections: Crawl Stats and Coverage. These areas offer detailed information about Googles crawling behavior and any issues its encountering.
Crawl Stats Report
The Crawl Stats report shows how often and how deeply Googlebot is crawling your site. It includes data on total crawl requests, average response time, and the number of kilobytes downloaded per day. This helps you see if there are performance issues that might affect crawlability.
| Metric | Description | Why It Matters |
|---|---|---|
| Total Crawl Requests | Total number of times Googlebot requested pages | High volume may indicate healthy indexing; sudden drops could signal problems |
| Total Download Size | The amount of data downloaded by Googlebot | Larger sizes may slow down crawling; optimize assets for faster access |
| Average Response Time | How long your server takes to respond to requests | Slow response times can lead to fewer crawled pages |
Coverage Report
The Coverage report highlights indexing issues across your site. Its divided into four main categories: Error, Valid with warnings, Valid, and Excluded. Pay close attention to the “Error” section—it points out critical crawl issues like 404s or server errors.
| Status Type | Description | Suggested Action |
|---|---|---|
| Error | Pages that couldnt be indexed due to serious issues (e.g., 404, server errors) | Fix broken links, check server uptime, and resolve redirect loops |
| Valid with Warnings | Pages indexed but with potential issues (e.g., mobile usability problems) | Review each warning to ensure its not affecting SEO performance |
| Valid | Successfully indexed pages without known issues | No action needed, but monitor regularly for changes |
| Excluded | Pages intentionally or unintentionally left out of the index (e.g., via noindex) | Review exclusion reasons to confirm theyre intentional or need correction |
Tips for Reading and Acting on the Data
#1 Check Regularly
Crawl issues can appear at any time—especially after a site update or migration. Make it a habit to check GSC weekly.
#2 Prioritize Errors First
Tackle critical errors before anything else. They have the biggest impact on whether your content appears in search results.
#3 Use URL Inspection Tool
If youre unsure why a specific page isnt being crawled or indexed, plug it into the URL Inspection Tool for real-time feedback from Google.
#4 Correlate With Server Logs (Optional)
If you manage a large website, compare GSC crawl stats with your server logs to get a fuller picture of bot activity.
Your Next Step as a Webmaster
By regularly reviewing these reports and understanding what they mean, youll be better equipped to prevent or quickly fix crawl errors. Staying proactive ensures that Google has smooth access to all your important content—which ultimately helps improve your visibility in search results.
4. Fixing and Preventing Crawl Errors
Crawl errors can hurt your website’s visibility on search engines, but the good news is that most of them can be fixed—and even prevented—with the right strategies. Let’s walk through some practical steps you can take to resolve crawl errors and keep them from coming back.
Common Fixes for Crawl Errors
Below are some of the most frequent types of crawl errors and how you can fix them:
| Error Type | Cause | How to Fix It |
|---|---|---|
| 404 Not Found | The page doesn’t exist or was deleted. | Create a redirect to a relevant page or restore the missing content. |
| Soft 404 | The page returns a “200 OK” status but has no useful content. | Add valuable content or return a proper 404 status code. |
| Server Errors (5xx) | The server fails to respond correctly. | Check server logs, increase server resources, or contact your hosting provider. |
| Blocked by robots.txt | Your robots.txt file disallows important pages. | Edit your robots.txt file to allow crawling of key areas. |
| Redirect Errors | Busted or endless redirect chains. | Simplify redirects and ensure they lead to live pages. |
Using Redirects Wisely
If youve removed a page or changed its URL, setting up 301 redirects is a smart move. A 301 redirect tells search engines that the page has permanently moved, which helps preserve SEO value. Avoid using too many chained redirects, as they can slow down crawlers and users alike.
Tweaking Your robots.txt File
Your robots.txt file guides search engine bots on what they can and cant access. Make sure youre not accidentally blocking important folders or files. For example:
User-agent: * Disallow: /private/ Allow: /public/This setup blocks bots from crawling anything under “/private/” but allows access to “/public/”. Review this file regularly, especially after site structure changes.
Sitemap Optimization Tips
A clean, up-to-date sitemap makes it easier for search engines to index your content efficiently. Here are some best practices:
- Only include URLs that return a 200 status code (no errors or redirects).
- Avoid adding noindex or canonicalized pages in your sitemap.
- If you have a large site, break your sitemap into multiple smaller sitemaps (each under 50,000 URLs).
Sitemap Example Structure:
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"> <url> <loc>https://www.example.com/page1</loc> <lastmod>2024-05-01</lastmod> </url> </urlset>This format ensures compatibility with Google Search Console and other search engines.
Create a Habit of Monitoring
Crawl errors are often symptoms of ongoing issues. Make it part of your workflow to check tools like Google Search Console weekly for new errors. The sooner you catch them, the faster you can fix them before they impact rankings or user experience.