Each one is a check that runs, described by the engine itself. If a check changes, this page changes with it.
HTTP status
http_statusThe status of the final response after redirects. Fails on anything outside the 2xx range, because a URL that does not answer 200 has no document to index; warns on a 2xx that is not 200. Reports not_measurable when the audit was run against supplied HTML rather than a live fetch.
Fixing it: Gives search engines a document to index at this URL at all.
Redirect chain
redirect_chainEvery hop followed to reach the page. Fails on a loop, on any hop through plain http, and at 3 or more hops; warns above 1. Each hop costs crawl budget and adds latency for every visitor.
Fixing it: Cuts latency for every visitor and stops crawl budget being spent on hops.
HTTPS
transport_securityThe scheme of the final URL and whether a Strict-Transport-Security header was returned. Plain http fails; https without HSTS warns, because the first request of a session can still go out in the clear.
Fixing it: Removes the browser "not secure" warning and satisfies a confirmed ranking signal.
robots.txt
robots_txtThe origin /robots.txt, parsed to RFC 9309: consecutive user-agent lines share a group, the most specific group wins, and the longest matching pattern decides with Allow winning ties. Fails when the audited path is disallowed for Googlebot; warns when the file is absent or declares no Sitemap. Distinct from the robots meta tag: a disallow here stops the crawl, not just the indexing.
Fixing it: Lets crawlers read the page, so every other signal on it can be seen.
Robots meta directives
robots_metaDirectives across meta robots, googlebot, bingbot and googlebot-news tags. A noindex or none directive fails the check outright because it removes the page from search regardless of every other signal; nofollow warns because it strips the page of its outbound crawl value.
Fixing it: Removes a directive that keeps the page out of search regardless of its content.
X-Robots-Tag header
x_robots_tagIndexing directives delivered in the response header rather than the markup, including any bot-name prefix. A noindex or none fails; nofollow warns. This is checked separately from the robots meta tag because the two disagree often and a header-level noindex is invisible in the HTML.
Fixing it: Removes a header-level block that keeps the page out of the index entirely.
Canonical URL
canonicalPresence of <link rel="canonical">, whether its href is absolute in the markup, whether it resolves to the audited URL itself, and whether more than one canonical is declared. A missing or conflicting canonical lets parameter and trailing-slash variants compete with the page.
Fixing it: Consolidates duplicate URL variants onto one address, so ranking signals stop being split.
XML sitemap
sitemapDiscovery via the robots.txt Sitemap directive then the conventional paths, followed by XML validation. Fails when nothing retrieved parses, or when a file breaks the 50,000 URL or 50 MB protocol limits; warns on relative or cross-host <loc> values, on partial parse failures, and when a valid sitemap does not list the audited page.
Fixing it: Shortens the delay between publishing a page and it being discovered.
Server-rendered content
render_dependencyVisible text as a share of the response body, plus inline script share and server-rendered word count. Fails under 60 words alongside a script-heavy document, or below a 2% text ratio; warns below 5%. SEOAST executes no JavaScript, so this measures what a crawler sees before deciding whether to queue a rendered pass.
Fixing it: Puts the content in the first response, where every crawler reads it, instead of behind a render pass that is neither fast nor guaranteed.