What's the difference between 404 and 410?

Both say the page doesn't exist and both lead to removal from the index. A 410 (“gone”) may be processed slightly faster, but in practice the difference is small.

A page that returns 200 but looks like an error or an empty page, such as “No products found”, or a mass redirect to the homepage. Google treats it like a 404.

How long does Google tolerate 5xx errors?

A short outage slows crawling. If errors persist longer (several days), Google starts dropping pages from the index. For planned maintenance, use 503 rather than 500.

HTTP status codes and SEO

An HTTP status code is the three-digit number a server sends back with every response. For SEO the rule is simple: a page that should appear in results must return 200. 3xx codes redirect, 4xx say the page doesn't exist, and 5xx say the server has a problem — during a longer outage Google starts removing pages from the index.

The status codes that matter for SEO

Code	Meaning	What Google does
200	OK	indexes the content (unless noindex)
301, 308	moved permanently	indexes the target URL
302, 307	moved temporarily	usually keeps the old URL
304	not modified	uses the version it already has
404	not found	removes from the index
410	gone	removes from the index
429	too many requests	slows crawling
500	server error	slows crawling, removes after a long outage
503	service unavailable	like 500; the right code for maintenance

More on redirects: 301 vs 302 and chains and loops.

When to act immediately

a page that brought traffic returns 404 or 410 — it was removed or its URL changed without a redirect,
a series of 5xx errors — an overloaded server or a failure after a release,
robots.txt returns 5xx — Google pauses crawling of the whole site,
a content page starts redirecting — someone changed the server rules.

Soft 404

The hardest case to catch: the server returns 200, but the content is an error message, an empty category or the homepage after a mass redirect. Google flags these URLs as soft 404 and leaves them out of the index.

How to check a status code

The redirect checker shows the status of every hop and the final page for up to 10 URLs at once. In a browser, you'll find it in the developer tools, on the Network tab.

Monitoring

We tell "the page is down" from "we couldn't check" — a block by the site's security isn't a page outage.

IndexRise checks the status code of monitored pages every night. A 4xx or 5xx on a page that used to return 200 is a critical event. A series of server errors is reported right away, others after confirmation on the next check.