How to Find and Fix Site Crawler Errors

What is "Site Crawler Errors"?

Site crawler errors are notifications from automated bots, like those from search engines, indicating they encountered a problem when trying to access or process a page on your website. These errors create a gap between your actual site content and what search engines can see and index.

Ignoring these errors leads to wasted marketing efforts, as important pages may be invisible in search results, and technical issues can degrade user experience without your knowledge.

Crawl Budget: The limited number of pages a search engine bot will crawl on your site within a given time. Errors waste this budget on broken pages instead of valuable content.
HTTP Status Codes: Numeric codes returned by your server. Key error codes include 404 (Not Found), 5xx (Server Errors), and 403/401 (Access Forbidden/Unauthorized).
Robots.txt: A file that instructs crawlers which parts of your site to avoid. Misconfigurations here can accidentally block critical pages.
XML Sitemap: A file listing all important pages you want crawled. Errors occur if it contains broken links or points to blocked pages.
Soft 404: A page that returns a "200 OK" success code but shows error content (like "product not found"), misleading crawlers and users.
Canonicalization Issues: When multiple URLs display the same content, confusing crawlers about which version is the primary one to index.
Server Log Analysis: Reviewing raw server logs to see exactly how and when crawlers access your site, revealing patterns errors in tools might miss.
Index Coverage Report: A tool within Google Search Console that provides a detailed inventory of your site's pages in Google's index and the errors preventing inclusion.

This topic is critical for marketing managers and product teams responsible for online visibility, as unresolved errors directly sabotage SEO performance and lead generation. For founders and procurement leads, understanding this area is key to evaluating the health of their digital assets and the competence of vendors they might hire to fix issues.

In short: Site crawler errors are technical roadblocks that prevent search engines from properly seeing and listing your website's pages, directly harming your organic traffic.

Why it matters for businesses

When businesses ignore crawler errors, they are essentially leaving revenue on the table by allowing technical faults to hide their products, services, and content from potential customers actively searching for them.

Lost Organic Traffic & Leads: Pages with critical errors are not indexed. This means they receive zero search traffic, turning potential customer inquiries into missed opportunities.
Wasted Marketing Budget: Investment in content creation and SEO for pages that crawlers cannot access yields no return, effectively burning the allocated budget.
Poor User Experience: Errors like broken links or slow server timeouts frustrate users who do find your site, increasing bounce rates and damaging brand perception.
Inefficient Crawl Budget Use: Search engines waste time attempting to crawl broken URLs instead of discovering your new, high-value content, slowing down how quickly your updates appear in search.
Competitive Disadvantage: While your site has hidden barriers, competitors with clean technical foundations will rank more easily and capture your market share.
Misleading Data & Reporting: Soft 404s and other masked errors pollute your analytics, making it seem like pages are performing when they are actually showing error states to visitors.
Compromised Site Authority: A high volume of server errors (5xx) can signal to search engines that your site is unreliable, potentially leading to a broader ranking decline.
Blocked Key Processes: A misconfigured robots.txt file can accidentally block crawlers from your entire checkout or login system, preventing search engines from understanding key parts of your business.

In short: Unresolved crawler errors silently erode your website's ability to attract and convert customers through search, impacting revenue and growth.

Step-by-step guide

Resolving crawler errors can feel overwhelming due to the technical nature of the reports, but a systematic approach makes it manageable.

Step 1: Access Your Crawl Error Data

The initial obstacle is not knowing where to look. The primary source is Google Search Console. Verify your site's ownership and navigate to the "Indexing" section, then "Pages" and "Page indexing" to see the Index Coverage report. This is your master list of issues Google's crawler has encountered.

Step 2: Categorize and Prioritize Errors

The report lists many errors; tackling them randomly is inefficient. Prioritize based on business impact:

Server errors (5xx): Fix these immediately, as they affect site accessibility.
Soft 404s on key commercial pages: High priority, as they mislead users and search engines on important product or service pages.
Submitted URL blocked by robots.txt: High priority if the page is important for traffic or conversions.
404 errors on pages that previously had traffic: Medium priority; redirect these to preserve link equity.
404 errors on new or unknown pages: Lower priority; these may be legacy or test pages.

Step 3: Investigate Server Errors (5xx)

These indicate your web server is failing. Start by checking your server's error logs for the exact time of the crawl. Common causes are exhausted memory, database connection failures, or faulty plugin/script. Contact your hosting provider or development team with the specific error codes and timestamps.

Step 4: Fix Access Issues (4xx and robots.txt blocks)

For 403/401 errors, verify file permissions and ensure no security plugins are overly restrictive. For URLs blocked by robots.txt, review the file (located at yourdomain.com/robots.txt). Ensure you are not accidentally using "Disallow: /" or blocking crucial directories like /css/ or /js/ that contain site resources.

Step 5: Address "Not Found" (404) Errors

For each 404, decide on the correct action:

If the page should exist: Restore it or fix the broken internal link pointing to it.
If the page is gone but has backlinks or previous traffic: Implement a 301 redirect to the most relevant live page.
If the page is intentionally gone and unimportant: Let the 404 stand. You can use a "410 Gone" status to tell crawlers the removal is permanent.

Step 6: Resolve "Soft 404" Errors

These are deceptive because the server says the page is OK. Check the URL manually. If it shows "product not found" or similar, you must either restore the actual content or change the server's response to a true 404 or 410 status code. For e-commerce sites, ensure out-of-stock product pages handle this correctly.

Step 7: Validate Your XML Sitemap

An error-filled sitemap misdirects crawlers. In Google Search Console, go to "Sitemaps." Ensure your sitemap is submitted and check for errors. The sitemap should only contain canonical URLs (no duplicates) and must not list pages blocked by robots.txt or returning errors.

Step 8: Monitor and Re-crawl

After making fixes, you must prompt Google to re-crawl the affected URLs. In Search Console, use the "URL Inspection" tool for key pages and click "Request Indexing." For broader issues, updating and re-submitting your sitemap can trigger a wider re-crawl. Monitor the Coverage report over the following days to confirm errors decrease.

In short: Systematically identify errors in Search Console, prioritize by business impact, implement technical fixes, and then request re-crawling to validate your solutions.

Common mistakes and red flags

These pitfalls are common because they often seem like quick fixes or are misunderstood nuances of technical SEO.

Redirecting every 404 to the homepage: This creates a poor user experience and dilutes page-specific "link equity." Fix it by redirecting 404s only from important legacy pages to the most semantically relevant live page.
Ignoring "Crawled - currently not indexed" status: This is not an error but a warning sign. It often means the page is thin, duplicate, or low-quality. Address it by improving content depth and uniqueness.
Blocking CSS and JavaScript in robots.txt: This prevents search engines from rendering your page fully, harming understanding and rankings. Fix it by allowing crawlers access to all essential resources.
Fixing the error but not requesting re-indexing: Crawlers may not revisit the page for weeks, delaying the fix. Always use the "Request Indexing" feature in Google Search Console after a correction.
Not checking for mobile vs. desktop errors separately: Your site may have different configurations. Check the Mobile Usability report and ensure your mobile version is equally crawlable.
Overlooking international/geo-targeted errors: If you have country-specific sites (ccTLDs or subdirectories), crawler errors must be checked for each version in its respective Search Console property.
Treating a soft 404 as a low priority: Because it returns a "200 OK" code, it's often ignored. This misleads both users and algorithms. Fix it by ensuring error pages return correct 4xx status codes.
Using generic 404 error pages with no navigation: This dead-ends users, increasing bounce rates. Avoid it by creating helpful 404 pages with a search bar, main navigation links, and popular content suggestions.

In short: Avoid superficial fixes that harm user experience or fail to signal corrections to search engines, and always verify crawler access across all site versions and resource types.

Tools and resources

Choosing the right tool depends on whether you need discovery, diagnostics, or ongoing monitoring.

Search Console Platforms: The essential, free tool for seeing errors Google's crawler finds. Use it for primary diagnostics and validation. Bing Webmaster Tools provides the same for the Bing search engine.
Server Log File Analysers: Tools that parse your raw server logs. Use these to see the exact crawl frequency, catch errors that might not appear in Search Console, and understand crawl budget consumption in detail.
Website Crawling Suites: Software that simulates a search engine bot to crawl your entire site. Use these for a comprehensive, internal audit to find broken links, status code errors, and sitemap issues before a search engine does.
Website Monitoring Services: External tools that check your site's uptime and response codes from various global locations at regular intervals. Use these to catch sporadic server errors (5xx) that occur outside of search engine crawl times.
Chrome Developer Tools: A free browser feature. Use the "Network" tab to manually check the HTTP status code and loaded resources (like CSS/JS) for any specific page, simulating a crawler's initial fetch.
robots.txt Testing Tools: Validators offered within Google Search Console or as standalone online tools. Use these to test new robots.txt rules before deploying them live to ensure you aren't accidentally blocking critical content.
Redirect Mapping Tools: Software that follows chains of redirects. Use these to audit existing redirects for loops, long chains, or incorrect mappings that could cause crawl errors or waste crawl budget.

In short: Combine the free data from search engine consoles with proactive crawling and server log analysis for a complete view of your site's crawl health.

How Bilarna can help

Identifying the root cause of persistent crawler errors often requires specialized expertise, but finding a competent and trustworthy technical SEO or development agency can be challenging.

Bilarna simplifies this process. Our AI-powered B2B marketplace connects you with verified software and service providers who specialize in technical SEO audits, website development, and hosting infrastructure. You can describe your specific crawl error challenges—such as recurring 5xx server issues or complex robots.txt configurations—and our system matches you with providers whose verified skills and project histories align with your needs.

Every provider on Bilarna undergoes a verification process, offering you a layer of trust and reducing the risk of engaging with unqualified vendors. This allows founders, marketing managers, and procurement leads to efficiently find the external expertise required to diagnose and resolve technical site errors, ensuring their website functions as a reliable asset for growth.

Frequently asked questions

Q: How often should I check for crawl errors?

For most active business websites, a weekly check of Google Search Console's Coverage report is sufficient. After making significant site changes (like a migration or redesign), monitor daily for at least two weeks. Set up email notifications within Search Console for critical issues like an increase in 5xx errors.

Q: Are some crawler errors acceptable to ignore?

Yes, but selectively. You can generally ignore 404 errors on URLs that were never important, such as old tag pages, temporary campaign links, or mistyped URLs that bots guess. The key is to ensure no valuable pages or pages with existing backlinks are returning errors. Always prioritize errors affecting pages that drive business value.

Q: Can too many redirects cause a crawl error?

While not a direct error in reports, long redirect chains (e.g., Page A > B > C > D) waste crawl budget and can slow down page loading. Search engines may stop following a chain after a certain point. Fix this by auditing redirects and updating them to point directly to the final destination URL with a single 301 redirect.

Q: What's the difference between a 404 and a 410 error?

Both mean a page is not found, but they send different signals. A 404 means "not found," but it could be temporary. A 410 means "gone," explicitly telling search engines the resource is permanently removed. Using a 410 for deleted content can help search engines drop the page from their index more efficiently.

Q: If I fix a crawl error, how long until it disappears from the report?

After you fix the error and successfully request indexing, it can take from a few days to several weeks for the report to update. Google needs to recrawl the URL and reprocess it. The "Last crawl" date in the URL Inspection tool shows you when it was last visited. Persistence is key; if an error remains after a month, your fix may not have worked correctly.