How Google Understands HTTP Status Codes: What Matters for SEO and What Doesn’t

When it comes to search engine optimisation (SEO), technical aspects often make a big difference. One such technical element is HTTP status codes — the responses your server sends when a user or bot requests a page from your website.

However, not all HTTP status codes impact your site’s visibility on Google. Recently, Google’s Search Relations team, including Gary Illyes and Martin Splitt, discussed how the search engine handles various HTTP status codes during a podcast episode of Search Off the Record.

In this article, we’ll break down which status codes matter for SEO, which ones Google ignores, and how to use this knowledge to optimise your website without overcomplicating things.

What Are HTTP Status Codes?

HTTP status codes are three-digit numbers that web servers send as a response to a request from a browser or crawler. These codes indicate whether the request was successful, if there was a redirection, an error, or something else entirely.

Here are the main categories of HTTP status codes:

• 1xx – Informational
• 2xx – Success
• 3xx – Redirection
• 4xx – Client errors
• 5xx – Server errors

Now let’s understand how Google views these status codes and what that means for SEO.

1xx Status Codes: Google Ignores Them Completely

The 1xx class of status codes are informational responses. They include codes like:

• 100 Continue
• 101 Switching Protocols
• 102 Processing
• 103 Early Hints

While these codes might help improve user experience in some cases (for example, early hints can help browsers load content faster), Google’s crawlers ignore them entirely.

Gary Illyes clarified this during the podcast:

“We are just going to pass through [1xx status codes] anyway without even noticing that something was in the 100 range. We just notice the next non-100 status code instead.”

So, if you’re putting effort into optimising 1xx responses for Google’s benefit — stop. It won’t affect your SEO.

3xx Status Codes: Google Cares About Permanent vs Temporary

The 3xx range covers redirection codes. The common ones include:

• 301 Moved Permanently
• 302 Found (Temporary Redirect)
• 307 Temporary Redirect
• 308 Permanent Redirect

SEOs often debate which of these to use and when. But Google’s view is more straightforward.

Illyes explained that Google primarily cares whether a redirect is permanent or temporary. The exact code number doesn’t matter as much. This information is mainly used during canonicalisation — the process where Google chooses which version of a page to index.

So, whether you use 301 or 308 for permanent redirects, it’s fine. Similarly, 302 or 307 will be treated as temporary.

Key Point:

Don’t get caught up in choosing the perfect redirect code. Just make sure you’re consistent in using permanent redirects for moved content and temporary ones when appropriate.

4xx Status Codes: Standard But Important

These status codes represent client-side errors, and they do impact SEO when not handled properly.

Some common 4xx codes include:

• 404 Not Found: The requested page doesn’t exist.
• 410 Gone: The page is intentionally removed.
• 403 Forbidden: Access is denied.

Google processes 404 and 410 as signals that content is no longer available. If Google sees a 404, it will drop the page from its index over time. A 410 is processed similarly, but slightly faster since it indicates a deliberate removal.

While Google understands these codes well, it’s crucial not to return them by mistake. For example, a broken internal link leading to a 404 page may reduce your site’s crawl efficiency and user experience.

Splitt even joked about 418 I’m a teapot, a joke status code that has no SEO relevance — but it highlights how some codes exist purely for fun or testing, and won’t affect your site’s rankings.

Network Errors in Search Console: Dig Deeper

Sometimes, you might see network errors in Google Search Console that don’t fall into the HTTP status code range.

These are often caused by lower-level network issues, such as problems with:

• TCP/IP
• DNS resolution
• SSL/TLS handshake
• Firewalls or content delivery networks (CDNs)

Illyes noted:

“Every now and then you would get these weird messages in Search Console that like there was something with the network… and that can actually happen in these layers that we are talking about.”

So, if you see crawl issues that don’t make sense, investigate your hosting infrastructure, DNS setup, or even server firewalls. The problem may not be with your website or application code at all.

Status Codes That Still Matter But Weren’t Discussed

While the podcast covered some important insights, a few critical status codes weren’t discussed but remain essential for SEO.

200 OK

This is the standard response when a page loads successfully. Google expects this for any content you want to be crawled and indexed.

500-Level Errors

These indicate server-side issues, such as:

• 500 Internal Server Error
• 502 Bad Gateway
• 503 Service Unavailable
• 504 Gateway Timeout

Repeated 5xx errors may prevent Google from crawling your site and can lead to temporary de-indexing if the issue persists.

429 Too Many Requests

This means your server is rate-limiting crawlers or users. If Googlebot receives too many 429 responses, it may reduce the crawl frequency, potentially affecting your site’s visibility and indexing speed.

Practical SEO Takeaways

Now that you understand how Google processes these HTTP status codes, here are some actionable steps:

1. Don’t Worry About 1xx Status Codes

They’re ignored by Google, so don’t waste time trying to optimise them for SEO purposes.

2. Use Permanent Redirects for Moved Content

Focus on using 301 or 308 for permanent changes. Temporary redirects (302 or 307) are fine when the change is not final.

3. Monitor and Fix 404 Errors

Keep an eye on your crawl reports in Google Search Console. Fix broken internal links, and if a page is gone for good, consider using a 410 response.

4. Investigate Network Errors Thoroughly

If you see strange crawl errors, check your hosting environment, CDN settings, or DNS configuration. It may have nothing to do with your actual website code.

5. Handle 500 Errors Promptly

Server errors can severely affect your site’s crawlability and indexing. Always ensure your hosting is reliable, especially during high-traffic periods.

6. Avoid Overusing 429 Responses

If you’re using rate limiting or firewall rules, make sure Googlebot is allowed to crawl your site without hitting limits.

Final Thoughts

Understanding HTTP status codes isn’t just a technical topic for developers — it’s essential for SEOs too. But as the Google team revealed, you don’t need to overthink it.

Focus on the core codes Google cares about. Implement redirects properly. Avoid server errors. And if something seems off in Search Console, look beyond the surface.

By keeping your site technically sound, you’re giving Google all the right signals — and that can make a real difference to your search performance.