Knowledge base v2.13.0 · Community edition · data through 2 October 2026
Thing · Concept
A page that tells users it does not exist (or is empty) but answers with 200; Google treats it as an error and drops it.
Glossary · Soft 404
A page that returns a success code (200) while its content looks like an error or an empty page. Google keeps it out of the index but may keep crawling it. A CDN captcha page served with 200 is a common cause.
Documented in
A soft 404 is a page that returns a success code while its content looks like an error or an empty page. It is kept out of the index but continues to be crawled, wasting crawl budget.
Google, Google Search Central · Day 1 · How crawling errors affect Search
Google's status code page says that with a 204 No Content response Google receives no content and cannot process it, and that a 2xx page whose content is empty or an error message shows as a soft 404 in Search Console.
Google's JavaScript guides say that when client-side routing makes a real 404 status impractical, a single-page app can avoid soft 404s by redirecting with JavaScript to a URL whose server returns 404, or by adding a robots noindex meta tag with JavaScript.
Google Search Central · Day 2 · Lightning session D: Rendering and JavaScript
For client-side rendered single-page apps, where meaningful status codes can be impossible or impractical, Google's documentation gives two ways to avoid soft 404s: a JavaScript redirect to a URL that returns a 404 status, or a noindex robots meta tag added with JavaScript.
Google Search Central · Day 2 · What is Google friendly JavaScript
Google's site move guide says not to redirect many old URLs to one irrelevant destination such as the new site's home page, which can confuse users and might be treated as a soft 404, and to return a 404 or 410 for deleted or merged content that is not moved to the new site.
Google Search Central · Day 2 · Lightning session E: Managing Duplicates and Site Moves
Slide and stage claims that name it, the ones Google’s documentation does not cover first.
Because error pages are worded in endless variations, of which 'page not found' is only the classic one, Google cannot detect soft 404s with simple error, word or keyword matching.
Gary Illyes · Day 2 · Understanding what's on a page
Mistakes in Google's own systems are a further cause of soft 404s, and Gary Illyes asked site owners to report such mistakes in Google's forums.
Gary Illyes · Day 2 · Understanding what's on a page
Google detects soft 404s with a language model, described as something like BERT, that is trained to understand the structure and layout of a page as well as its language, instead of reading the page as one flat wall of text.
Gary Illyes · Day 2 · Understanding what's on a page
For soft 404 detection, the position of error text decides: an error in a less important part such as the navigation need not make a page a soft 404, but an error message alone in the main content, like 'Error establishing a database connection', does, much as a human would judge it.
Gary Illyes · Day 2 · Understanding what's on a page
Google's soft 404 detection tells the page chrome, such as navigation and footer, apart from the main content by analysing the page's visual hierarchy alongside its text.
Gary Illyes · Day 2 · Understanding what's on a page
Google clusters duplicate pages by content in four ways: exact matches, near matches, structurally similar content, and soft 404s.
'Crawled – currently not indexed' is most of the time a quality issue rather than a technical one: the pages are usually low quality or useless for the index, for example duplicates or soft 404s.
Soft 404s were named as a crawl problem alongside DNS and firewall issues, and described as one of the biggest problems on the internet right now for crawling and showing up in Search.
Gary Illyes · Day 1 · How crawling errors affect Search
Soft 404 pages are still crawled like normal pages; their bigger consequences are for indexing, and they also affect crawling.
Cherry Prommawin · Day 1 · How crawling errors affect Search
CDN captcha challenges often return HTTP 200; Googlebot does not solve them and sees only content with a 200 status, which indexing then classifies as a soft 404, reported as an error in Search Console.
Gary Illyes · Day 1 · How crawling errors affect Search
The fix for a client-side soft 404 is to make a missing page end with a real HTTP 404 status code instead of 200.
Rebecca Yu · Day 2 · Lightning session D: Rendering and JavaScript
Google listed four common JavaScript problems for indexing: content not present in the rendered HTML, using # in URLs for content changes, soft 404s and blocked resources.
Erin Sparling · Day 2 · What is Google friendly JavaScript
The fix for a client-side soft 404 is to serve a real 404 error page where appropriate; how to detect URLs that do not exist depends on how the app works and where it is hosted.
Erin Sparling · Day 2 · What is Google friendly JavaScript
Gary Illyes said soft 404 detection keeps searchers from clicking into dead ends and avoids wasting site owners' resources on visitors sent to error pages.
Gary Illyes · Day 2 · Understanding what's on a page
Soft 404 pages are another reason Google clusters pages together, an outcome site owners usually do not want.
Index selection applies the negative signals that immediately block indexing: noindex (the likely reading of one unclear word), expired unavailable_after dates, soft 404s, non-canonical duplicates, spam signals and other policies.
Index selection drops soft 404 pages that were not dropped earlier, for example when a document is reprocessed.
A soft 404 is a 404 in disguise: the page returns 200 but its content says something like 'page not found', information the site should have sent as the HTTP status.
Cherry Prommawin · Day 1 · How crawling errors affect Search
Google said soft 404s, like some other problem categories, are looked up in Search Console's page indexing report, while other crawl issues are debugged in the Crawl Stats report.
Gary Illyes · Day 1 · How crawling errors affect Search
A page that renders empty for Google, such as a client-side product page hit by these mistakes, is seen as thin content and ends up treated as a soft 404 even though users see a full page.
Rebecca Yu · Day 2 · Lightning session D: Rendering and JavaScript
Google's slide defined a soft 404 in a JavaScript application as a page that serves a 'Not Found' message but returns a 200 HTTP status code.
Erin Sparling · Day 2 · What is Google friendly JavaScript
In JavaScript single-page apps, soft 404s typically arise because the server returns the app with a 200 status for every URL, so when the app shows a 'not found' message for a URL that does not exist, no error is reported.
Erin Sparling · Day 2 · What is Google friendly JavaScript
A soft 404 is a page that should return an error status code but returns HTTP 200; from a crawling point of view it looks indexable, but because it has no real content Google throws it out of the index.
Gary Illyes · Day 2 · Understanding what's on a page
Google listed four common causes of soft 404s: pages that look like errors but are not, thin or empty content, server or CMS misconfigurations, and JavaScript-dependent content that fails to load.
Gary Illyes · Day 2 · Understanding what's on a page
An audience member reported recrawl intervals on one very large, popular client site: the homepage about 5 times a day, first-level pages about every 1.5 days (uncertain reading), and pages clustered as soft 404s every 160 to 190 days, adding that other sites will differ.
From the audience · Day 3 · How long does it take to..?
For temporary blocks return 503 or 429, never a 200 page with a captcha or error message, which becomes a soft 404 and can replace real content in the index. Verify Googlebot by reverse DNS, not by user agent.
Ibrahim Anjro · Day 1 · How crawling errors affect Search
Day 1 said a CDN captcha page served with HTTP 200 becomes a soft 404, while Day 2 (D2-C374, D2-C375) said such challenge pages are hard to recognise as errors and can be clustered as duplicates; Google's CDN post describes both outcomes, and in both the real pages drop out of Search.
Ibrahim Anjro · Day 1 · How crawling errors affect Search
After moving to real paths, set the server or hosting rewrite rules so a direct request to every valid path returns 200 with the content (ideally server-rendered) and an unknown path returns a 404 status, which removes client-side soft 404s at the source.
Ibrahim Anjro · Day 2 · What is Google friendly JavaScript
Return real error status codes for error states, 404 or 410 for missing content and 503 for outages such as a failed database connection, also in single-page apps; a 200 page whose main content is only an error message is treated as a soft 404 even when header and navigation look normal.
Ibrahim Anjro · Day 2 · Understanding what's on a page
Kit items about Soft 404: their own words name it, or several of the claims they rest on do.
Never serve error states, empty results or failed data loads with a 200 status
Rests on 10 claims, 7 of them naming Soft 404; its own words name Soft 404
Return a real 404 for unknown routes in single-page apps, or use a documented client-side fallback
Rests on 7 claims, 6 of them naming Soft 404
Return 404 or 410 for removed and non-existent URLs
Rests on 7 claims, 3 of them naming Soft 404; its own words name Soft 404
Watch the Page indexing report and treat its not-indexed reasons as a work list
Rests on 10 claims, 2 of them naming Soft 404; its own words name Soft 404
Never serve bot challenges or error pages to crawlers with a 200 status
Rests on 7 claims, 2 of them naming Soft 404; its own words name Soft 404
Answer planned maintenance and short outages with 503, for a day or two at most
Rests on 11 claims, 2 of them naming Soft 404; its own words name Soft 404
Redirect an old URL only to a page with the same intent, and return 404 or 410 when there is none
Rests on 7 claims, 1 of them naming Soft 404; its own words name Soft 404
Do not block JavaScript, CSS or API endpoints that pages need for rendering in robots.txt
Rests on 7 claims, 1 of them naming Soft 404; its own words name Soft 404
Also inglossary term Soft 404
Index selection applies the negative signals that immediately block indexing: noindex (the likely reading of one unclear word), expired unavailable_after dates, soft 404s, non-canonical duplicates, spam signals and other policies.
Index selection drops soft 404 pages that were not dropped earlier, for example when a document is reprocessed.
Things named in the same claim, with the number of claims they share.