Should you fix all the 404 and 500 errors flagged in Search Console?

Why does Google tolerate certain crawl errors?

Google makes a fundamental distinction between structural errors and temporary technical incidents. When its crawler encounters a page that responds with a 404 or 500, it does not immediately remove it from the index.

The engine retains the previously indexed version and attempts to crawl it again later. This logic safeguards against false positives: temporarily overloaded servers, restarts, traffic spikes, transient network issues.

What is the difference between a 404 error and a 500 error from an indexing perspective?

A 404 signifies the permanent absence of a resource: the page no longer exists, the server confirms this. Technically, this is a consistent and expected HTTP response for deleted content.

A 500 indicates a server malfunction: the page likely exists, but the server cannot deliver it for an internal reason. Google interprets the 500 as a potentially temporary incident, not as an intentional deletion.

The engine thus adopts two distinct strategies. For repeated 404s over several weeks, the page eventually gets removed from the index. For 500s, Google waits longer before making a drastic decision.

What actually happens with the 'retained index state'?

When an indexed page becomes temporarily inaccessible, Google does not abruptly deindex it. It keeps in memory the last successfully crawled version: content, meta tags, internal structure.

This version remains eligible for ranking in search results as long as the error persists. Users can still come across this URL in the SERPs, even if it now returns an error.

The risk? A degraded user experience if the error lasts too long. Google eventually removes the page if attempted recrawls consistently fail over several cycles.

• Temporary 404/500 errors do not lead to immediate deindexing
• Google retains the last crawled version as long as the error appears to be transient
• The duration of this tolerance varies depending on the site's usual crawl frequency
• A recurring error over several weeks will ultimately result in removal from the index
• 500s benefit from increased patience compared to 404s as they indicate a technical incident

Does this tolerance correspond to real-world observations?

Yes, but with important nuances depending on the site profile. On high-authority sites crawled daily, a one-day 500 error often goes unnoticed. The page remains indexed, and its ranking does not change.

On sites that are crawled less frequently, the same error can persist for several weeks before a new visit from Googlebot detects a return to normalcy. In the meantime, the page remains technically indexed but its content is not refreshed. If competitors publish similar content that's more recent, the ranking may slip.

The term "temporary" remains deliberately vague. Google provides no numeric threshold: 24 hours? 7 days? 30 days? This opacity forces SEOs to stay vigilant. [To be verified] based on industry and competition.

When does this rule not apply?

The first problematic case: 404 errors on strategic pages that were recently created. If a page has never been successfully crawled before returning a 404, Google has nothing to retain in memory. It will never be indexed.

The second exception: massive simultaneous errors. If 80% of the site suddenly switches to 500, Google may interpret this as a failed migration, a hack, or a major structural issue. Individual URL tolerance no longer applies: it's the overall health of the site that is called into question.

The third limitation: sites with an already saturated crawl budget. Google will not waste resources endlessly retrying URLs that fail. On a large e-commerce site with millions of pages, even a temporary error may simply push the URL to the back of the crawler’s queue.

Is Google telling the whole truth about 404s?

The official wording simplifies a more complex reality. Google internally distinguishes several types of 404s: those on URLs never crawled (normal), those on old migrated pages (acceptable if redirected), those on incorrectly generated URLs (crawl pollution).

The claim that "they can be ignored" mainly applies to the last case: 404s on fictitious URLs created by broken internal or external links. These errors have no direct negative impact on SEO. However, a 404 on an old high-traffic page represents lost revenue, even if technically Google can tolerate it.

What should you do when Search Console flags hundreds of 404s?

The first step: sort by volume of lost clicks. Search Console shows the number of times an error URL has been crawled. Focus on the pages that were receiving organic traffic recently: these are the ones generating real lost revenue.

404s on URLs never visited, never successfully crawled before, or generated by external bots can indeed be ignored. There’s no need to create 301 redirects to the homepage for ghost URLs that just pollute the logs.

For strategic pages that have turned into 404s, set up a 301 redirect to the closest equivalent content. If there is no logical equivalent for the page, leave it as a 404 rather than forcing an artificial redirect that would degrade the user experience.

How to handle lingering 500 errors?

A 500 error that persists beyond 48 hours merits investigation. It often signals a server configuration issue, a PHP timeout, a saturated database, or insufficient resources to generate the page.

Google may wait a few days, but user experience degrades immediately. A visitor encountering a 500 will likely not return. The bounce rate skyrockets, user signals deteriorate, and Google eventually considers this in the ranking.

Use the live URL test in Search Console to check if Google can indeed crawl the corrected page. Do not rely solely on your browser: the server-side rendering for Googlebot may differ from what you see in the frontend.

What indicators should you monitor to anticipate problems?

The Crawl Statistics report provides an overview of the number of responses by HTTP code over time. A sudden spike in 500 or 404 should trigger an immediate alert, even if these errors are individually tolerated.

Compare the number of error URLs with the total volume of indexed pages. If the ratio exceeds 5%, you likely have a structural problem that warrants thorough analysis: broken internal linking, poorly managed migration, automatic generation of defective URLs.

Monitoring tools complement Search Console by detecting issues before Googlebot encounters them. A site experiencing multiple undetected micro-outages risks having its crawl budget gradually eaten away.

• Filter 404s in Search Console by crawl volume and traffic history
• Ignore errors on URLs never indexed or generated by external bots
• Only redirect in 301 for strategic pages to a logical equivalent
• Investigate any 500 error that persists beyond 48 hours
• Monitor the error/indexed pages ratio in the Crawl Statistics report
• Use the live URL test to validate the resolution on Googlebot's side