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Every check Wrendex runs.
28 categories.

The full catalog of technical SEO checks Wrendex runs on every audit. Browse by category, drill into any individual check, and see the synthetic before/after we use to validate it. Every check ships on every plan - no asterisks, no add-ons.

Sec. C.00 · Index ◊Jump to a category 28 categories

01. Title

5 checks

TITLE_MISSING Page title missing The page has no <title> tag. Search engines fall back to the URL or a fragment of body text, which hurts click-through. error TITLE_TOO_LONG Title too long Titles wider than what Google shows (~580px on desktop) are truncated in search results, hiding the part that converts. Truncation depends on the rendered width of the characters, not just their count. warning TITLE_TOO_SHORT Title too short Very short titles miss ranking-relevant keywords and look thin in SERP listings. notice TITLE_MULTIPLE Multiple title tags More than one <title> tag was found. Browsers and crawlers pick one inconsistently. warning DUPLICATE_TITLE Duplicate title across pages Two or more pages share the same title, making them compete in search results. warning

02. Meta Description

5 checks

META_DESCRIPTION_MISSING Meta description missing Without a meta description, search engines auto-generate a snippet, which is rarely flattering for click-through. warning META_DESCRIPTION_TOO_LONG Meta description too long Descriptions wider than what Google shows (~985px on desktop) get truncated in SERP snippets, losing your final call to action. Truncation depends on the rendered width of the characters, not just their count. notice META_DESCRIPTION_TOO_SHORT Meta description too short Very short descriptions waste prime SERP real estate and miss keywords. notice META_DESCRIPTION_MULTIPLE Multiple meta descriptions More than one meta description tag is present; crawlers pick one unpredictably. warning DUPLICATE_META_DESCRIPTION Duplicate meta description Multiple pages share the same meta description, weakening relevance signals. notice

03. Headings

3 checks

H1_MISSING H1 missing The page has no H1. Crawlers and screen readers rely on it as the primary topic signal. warning H1_MULTIPLE Multiple H1 tags More than one H1 dilutes the primary topic signal and confuses screen readers. notice DUPLICATE_H1 Duplicate H1 across pages Multiple pages share the same H1, suggesting overlapping topics or templating gaps. notice

04. HTTP Status

6 checks

HTTP_404 404 Not Found The page returns 404. Search engines drop it from the index and inbound links waste their authority. error HTTP_403 403 Forbidden The server refused the request. Crawlers and users alike see a wall instead of content. error HTTP_409 409 Conflict The server reports the request conflicts with current state. Often a deployment or data race issue. error HTTP_4XX 4xx client error The page returned a 4xx response other than 403/404/409. The URL is unreachable for crawlers. error HTTP_500 500 Internal Server Error The server crashed handling this URL. Repeated 500s deindex the page over time. error HTTP_5XX 5xx server error The page returned a 5xx response. Search engines treat repeated 5xx as a removal signal. error

05. Indexability

6 checks

NOINDEX_PAGE Page is noindex The page sets robots noindex. Search engines will not include it in results. warning NOFOLLOW_PAGE Page-level nofollow All outbound links on this page are flagged nofollow at the page level, breaking internal link equity. notice NOINDEX_FOLLOW noindex, follow The page is noindex but follow. Often intentional, occasionally a leftover that hides ranking content. notice NOINDEX_NOFOLLOW noindex, nofollow The page blocks both indexing and link following. Inbound link authority is wasted. warning NOINDEX_CONFLICT Conflicting noindex signals Different sources (meta robots, X-Robots-Tag, sitemap) disagree on whether the page should be indexed. warning NOFOLLOW_CONFLICT Conflicting nofollow signals Meta robots and X-Robots-Tag disagree on follow / nofollow. notice

06. Markup

2 checks

INVALID_LANG Invalid lang attribute <html lang> is missing or not a valid BCP-47 tag. Search engines and screen readers cannot determine the page language. notice MISSING_VIEWPORT Missing viewport meta No <meta name="viewport"> tag. Mobile rendering will be broken and Google flags the page as non-mobile-friendly. warning

07. Content

1 checks

LOW_WORD_COUNT Thin content The page has very few words. Thin content rarely ranks and may be classified as low quality. notice

08. Performance

4 checks

SLOW_PAGE Slow page response Total response time is high. Slow pages cost rankings and conversions. warning OVERSIZED_HTML Oversized HTML The HTML payload is unusually large, slowing parsing and hurting Core Web Vitals. notice NO_COMPRESSION No HTTP compression The response is not gzip / br compressed, wasting bandwidth and slowing time-to-first-byte for clients. warning SLOW_TTFB Slow time-to-first-byte TTFB is high, indicating server or origin latency. This drags every other metric. warning

09. Internal Links

13 checks

NO_OUTGOING_LINKS No outgoing internal links The page links to nothing else on the site. Crawlers cannot use it as a hub. notice DOUBLE_SLASH_URL Double-slash in URL The URL contains a doubled slash, often produced by a templating bug, and can split crawl signals. notice TOO_MANY_URL_PARAMS Too many URL parameters The URL stacks many query parameters, which can fragment crawl coverage and confuse canonicalisation. notice ORPHAN_PAGE Orphan page No internal page links here. Search engines reach it only via the sitemap, with weak ranking signals. warning LINKS_TO_BROKEN Links to broken page This page links to a 4xx / 5xx URL on the site. Users hit dead ends and equity is wasted. error LINKS_TO_REDIRECT_INDEXABLE Links to redirected page The link target redirects to an indexable page. Working but wastes a hop and a little crawl budget. notice LINKS_TO_REDIRECT_NON_INDEXABLE Links to non-indexable redirect The link redirects to a URL the crawler cannot index. Equity is lost. warning LINKS_TO_BROKEN_NON_INDEXABLE Links to broken non-indexable The link target is both broken and non-indexable, so neither users nor crawlers can use it. warning NOFOLLOW_ONLY_INCOMING Only nofollow incoming links Every internal link to this page is nofollow. Search engines do not pass authority through. warning MIXED_FOLLOW_INCOMING Mixed follow / nofollow incoming Internal links to this page mix follow and nofollow, which is usually a templating accident. notice NOFOLLOW_OUTGOING_INTERNAL Nofollow on internal link An internal link is marked rel=nofollow, blocking authority flow on your own site. notice SINGLE_DOFOLLOW_INCOMING Only one dofollow incoming Just one internal page passes equity here. Single points of failure for crawl and rank. notice REDIRECT_NO_INCOMING Redirect with no incoming A redirect endpoint with no inbound internal links is dead weight in the link graph. notice

10. Images

5 checks

MISSING_ALT_TEXT Missing alt text An image has no alt attribute. Screen readers and image search cannot describe it. warning BROKEN_IMAGE Broken image The image URL returns an error. Users see a placeholder, search engines drop it from image results. error OVERSIZED_IMAGE Oversized image The image file is much larger than its rendered size, slowing the page. warning IMAGE_REDIRECT Image URL redirects The image src redirects, costing an extra round-trip on every load. notice MISSING_IMAGE_DIMENSIONS Missing image dimensions The image has no width / height attributes, which causes layout shift (bad CLS). notice

12. Redirects

10 checks

REDIRECT_302 302 temporary redirect The URL serves a 302. Crawlers may keep crawling the source if they expect it to come back. notice REDIRECT_3XX 3xx redirect The URL returns a non-301/302 redirect status. Browsers follow it but crawlers handle it inconsistently. notice BROKEN_REDIRECT Broken redirect The redirect target is a 4xx / 5xx response. Users land on an error. error REDIRECT_CHAIN Redirect chain More than one redirect hop before the final URL. Wastes crawl budget and slows users. notice REDIRECT_CHAIN_TOO_LONG Redirect chain too long The redirect chain has too many hops. Some crawlers stop following before the destination. warning REDIRECT_LOOP Redirect loop The redirect chain points back to itself. Browsers and crawlers give up. error HTTPS_TO_HTTP_REDIRECT HTTPS redirects to HTTP An HTTPS URL redirects to HTTP. This is a security and SEO regression. error HTTP_TO_HTTPS_REDIRECT HTTP to HTTPS redirect An HTTP URL redirects to HTTPS. Expected, but every internal link should target HTTPS directly to skip the hop. notice META_REFRESH_REDIRECT Meta refresh redirect The page uses a <meta http-equiv="refresh"> tag. Crawlers may treat it as a soft 200 instead of a redirect. warning TIMEOUT Request timed out The crawl request timed out. The URL is effectively unreachable for crawlers and slow users. error

13. Security

5 checks

HTTPS_LINKS_TO_HTTP HTTPS page links to HTTP An HTTPS page contains a plain HTTP link. Triggers mixed-content warnings on click-through. warning HTTP_LINKS_TO_HTTPS HTTP page links to HTTPS An HTTP page links to HTTPS. Usually fine, but suggests the page itself should also be HTTPS. notice HTTPS_CSS_TO_HTTP HTTPS page loads HTTP CSS Stylesheet loaded over HTTP from an HTTPS page. Browsers block it as mixed content. error HTTPS_JS_TO_HTTP HTTPS page loads HTTP JS Script loaded over HTTP from an HTTPS page. Blocked as mixed content; the page may break. error HTTPS_IMG_TO_HTTP HTTPS page loads HTTP image Image loaded over HTTP from an HTTPS page. Causes mixed-content warnings. warning

14. Hreflang

10 checks

INVALID_HREFLANG Invalid hreflang code An hreflang attribute has an invalid language / region code. warning HREFLANG_LANG_MISMATCH hreflang language mismatch The hreflang language does not match the actual page language. notice HREFLANG_MISSING_SELF_REF Missing self-referential hreflang An hreflang cluster must include a self-reference for each locale. This page omits its own. notice HREFLANG_MISSING_X_DEFAULT Missing x-default hreflang No x-default fallback is defined for users whose locale does not match any listed variant. notice HREFLANG_POINTS_TO_BROKEN hreflang target broken An hreflang entry points at a 4xx / 5xx URL. error HREFLANG_POINTS_TO_REDIRECT hreflang target redirects An hreflang entry redirects to another URL. Search engines may discount it. notice HREFLANG_MISSING_RECIPROCAL Missing reciprocal hreflang Page A links to page B via hreflang, but B does not link back. Without reciprocity, the cluster is ignored. warning HREFLANG_POINTS_TO_NON_CANONICAL hreflang target non-canonical An hreflang entry points at a URL whose canonical is something else. notice HREFLANG_MULTI_LANG_SINGLE_PAGE Multiple languages on one page The page declares hreflang for multiple language codes pointing at itself. notice HREFLANG_MULTI_PAGE_SINGLE_LANG One language across many pages Several pages claim to be the canonical for the same language code. notice

15. Canonical

8 checks

CANONICAL_POINTS_TO_4XX Canonical points to 4xx The canonical URL returns a 4xx error. The page has no valid canonical. error CANONICAL_POINTS_TO_5XX Canonical points to 5xx The canonical URL returns a 5xx error. error CANONICAL_POINTS_TO_REDIRECT Canonical points to redirect The canonical URL redirects. Search engines may follow it but the signal is weakened. warning CANONICAL_NO_INCOMING_LINKS Canonical has no incoming links The canonical URL is not linked anywhere internally, suggesting the cluster is fragmented. notice CANONICAL_HTTP_TO_HTTPS Canonical http to https The page is HTTP but its canonical is HTTPS. Expected during a migration; should not persist. notice CANONICAL_HTTPS_TO_HTTP Canonical https to http The page is HTTPS but the canonical is HTTP. Search engines may demote the page. error NON_CANONICAL_AS_CANONICAL Non-canonical declared as canonical The page sets itself as canonical but other pages declare a different canonical for the same content. warning DUPLICATES_NO_CANONICAL Duplicates without canonical Multiple pages share the same content but none declare a canonical. warning

16. Duplicates

1 checks

IDENTICAL_CONTENT Identical content Two or more pages serve identical body content. warning

17. CSS

3 checks

BROKEN_CSS Broken stylesheet A linked stylesheet returns an error response. The page renders without its styles. error OVERSIZED_CSS Oversized stylesheet A stylesheet is unusually large, slowing page render. warning REDIRECTED_CSS Stylesheet redirects A linked stylesheet URL redirects, costing an extra round-trip. notice

18. JS

3 checks

BROKEN_JS Broken script A linked script returns an error. The page may behave incorrectly. error OVERSIZED_JS Oversized script A script bundle is unusually large, hurting time-to-interactive. warning REDIRECTED_JS Script redirects A script URL redirects, adding a round-trip on every page load. notice

19. External Links

6 checks

EXTERNAL_LINK_3XX External link redirects An outbound external link redirects, costing user time. notice EXTERNAL_LINK_4XX External link broken (4xx) An outbound external link returns a 4xx error. warning EXTERNAL_LINK_BLOCKED External link blocked The external host blocked our crawler. Could be intentional bot blocking. notice EXTERNAL_LINK_5XX External link 5xx An outbound external link returned a 5xx error. warning EXTERNAL_LINK_TIMEOUT External link timeout The external link timed out during the crawl. notice EXTERNAL_LINK_5XX_REDIRECT External redirect to 5xx The external link redirects to a server-error response. warning

20. Render-Blocking

2 checks

RENDER_BLOCKING_CSS Render-blocking CSS A stylesheet blocks first paint. Hurts Largest Contentful Paint and perceived speed. warning RENDER_BLOCKING_JS Render-blocking JS A script in the <head> blocks rendering until parsed and executed. warning

21. Robots.txt

1 checks

ROBOTS_TXT_INACCESSIBLE robots.txt inaccessible robots.txt could not be fetched. Crawlers may treat the entire site as disallowed. error

22. Cross-Crawl Changes

6 checks

TITLE_CHANGED Title changed The page title changed since the previous crawl. notice META_DESCRIPTION_CHANGED Meta description changed The meta description changed since the previous crawl. notice H1_CHANGED H1 changed The H1 changed since the previous crawl. notice WORD_COUNT_CHANGED Word count changed The page word count moved meaningfully between crawls. notice REDIRECT_TARGET_CHANGED Redirect target changed A redirect now points at a different URL than in the previous crawl. warning BECAME_NON_INDEXABLE Page became non-indexable A previously indexable page is now blocked from indexing. warning

23. Sitemap

10 checks

SITEMAP_3XX_REDIRECT Sitemap URL redirects A URL listed in the sitemap redirects. notice SITEMAP_4XX Sitemap URL returns 4xx A URL in the sitemap is broken. error SITEMAP_403_FORBIDDEN Sitemap URL forbidden A URL in the sitemap returns 403. Search engines cannot index it. error SITEMAP_5XX Sitemap URL returns 5xx A URL in the sitemap returns a server error. error SITEMAP_NOINDEX Sitemap URL is noindex A URL in the sitemap is marked noindex. The two signals contradict each other. warning SITEMAP_NON_CANONICAL Sitemap URL non-canonical A URL in the sitemap is not the canonical version of its page. notice SITEMAP_TIMEOUT Sitemap URL timed out A URL in the sitemap timed out during the crawl. warning INVALID_SITEMAP_FORMAT Invalid sitemap format The sitemap could not be parsed as valid XML / sitemap protocol. error MISSING_FROM_SITEMAP URL missing from sitemap A linked, indexable URL is not present in any sitemap. notice DUPLICATE_IN_SITEMAPS Duplicate URL in sitemaps The same URL appears in more than one sitemap or more than once in the same sitemap. notice

24. Structured Data

10 checks

JSON_LD_PARSE_ERROR JSON-LD parse error A JSON-LD script block could not be parsed as valid JSON. error JSON_LD_MISSING_TYPE JSON-LD missing @type A JSON-LD object has no @type. Search engines cannot interpret it. warning JSON_LD_INVALID_TYPE JSON-LD invalid @type The @type does not exist on schema.org or is misspelled. warning JSON_LD_INVALID_PROPERTY JSON-LD invalid property A property on the JSON-LD object is not defined for the declared @type. notice JSON_LD_UNEXPECTED_PROPERTY_TYPE JSON-LD wrong property type A property's value type does not match the schema.org expected type (for example, string instead of Date). notice JSON_LD_UNEXPECTED_PROPERTY JSON-LD unexpected property An unrecognised property appeared on a JSON-LD object. notice JSON_LD_INVALID_VALUE JSON-LD invalid value A property's value is not in the expected format (for example, malformed URL). notice JSON_LD_DUPLICATE_PROPERTY JSON-LD duplicate property The same property is declared more than once on a JSON-LD object. notice JSON_LD_DEPRECATED_TYPE JSON-LD deprecated type The JSON-LD object uses a schema.org type that has been deprecated. notice JSON_LD_DEPRECATED_PROPERTY JSON-LD deprecated property The JSON-LD object uses a property that has been deprecated. notice

25. Structured Data (Google)

9 checks

JSON_LD_GOOGLE_MISSING_REQUIRED Google rich result missing required field A field Google requires for the rich result is missing. The page is ineligible until it is added. warning JSON_LD_GOOGLE_MISSING_ONE_OF_REQUIRED Google rich result missing one-of required Google requires at least one of a set of fields and none are present. warning JSON_LD_GOOGLE_PROPERTY_MISSING_TYPE Google rich result property missing type A nested object that Google expects to be typed has no @type. notice JSON_LD_GOOGLE_MISSING_IMAGE Google rich result missing image Google's rich result for this type requires an image and none was provided. warning JSON_LD_GOOGLE_INVALID_DATE Google rich result invalid date A date field is not in ISO 8601 format. notice JSON_LD_GOOGLE_UNRECOGNIZED_PROPERTY Google rich result unrecognised property A property is not recognised by Google for this rich-result type. notice JSON_LD_GOOGLE_UNRESOLVED_ID Google rich result unresolved @id An @id reference does not match any object on the page. notice JSON_LD_GOOGLE_EMPTY_FIELD Google rich result empty field A field that should hold a value is empty. notice JSON_LD_GOOGLE_INVALID_VALUE Google rich result invalid value A field's value is outside the format Google expects. notice

26. AMP

3 checks

AMP_VALIDATION_ERRORS AMP validation errors The AMP variant has validation errors and is ineligible for AMP-specific surfaces. warning AMP_CANONICAL_MISMATCH AMP canonical mismatch The AMP page and its canonical disagree on the canonical URL. notice AMP_EXCESSIVE_CSS AMP excessive CSS The AMP page exceeds the CSS budget allowed by the AMP spec. notice

27. Duplicate Code

2 checks

DUPLICATE_JS_CODE Duplicate JavaScript Multiple script bundles ship the same code, wasting bandwidth and parsing time. notice DUPLICATE_CSS_CODE Duplicate CSS Multiple stylesheets ship the same rules, inflating CSS payload. notice

28. Billing

1 checks

OUT_OF_CREDITS Crawl stopped: out of credits This crawl was aborted because the tenant ran out of credits before all pages could be fetched. Already-crawled pages are persisted; the report is partial. error

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