All 125 checks

The full reference. Each check has an id you'll see in the app and in exports, a severity, and fix guidance. Errors hurt indexing or users now; warnings are likely problems; opportunities are improvements.

Errors (29)

Client Error (4xx)response.4xx Server Error (5xx)response.5xx Connection Errorresponse.error Redirect Loopredirect.loop Redirect to Broken URLredirect.to_4xx Missing Titletitle.missing Canonical to Non-Indexable URLcanonical.non_indexable_target Multiple Canonicalscanonical.multiple Multiple Conflicting Canonicalscanonical.conflicting Non-Indexable URL in Sitemapindex.noindex_in_sitemap Links to Broken Internal URLlink.broken_internal Links to Localhostlink.localhost Broken Imageimage.broken Lorem Ipsum Placeholdercontent.lorem_ipsum Missing Return Linkhreflang.missing_return Invalid hreflang Valuehreflang.invalid_lang hreflang to Non-200 URLhreflang.non_200_target Structured Data Validation Errorsschema.validation_error Invalid JSON-LDschema.invalid_json Insecure Formsecurity.insecure_form Head Tags Outside <head>validation.head_tags_in_body Canonical Mismatch (Rendered vs Raw)js.canonical_mismatch Non-200 Pagination URLpagination.non_200_target Pagination Looppagination.loop Non-200 AMP URLamp.non_200_target AMP Page Missing Canonical to Non-AMPamp.missing_canonical Accessibility: Critical Violationsa11y.critical Content Wider Than Screenmobile.content_wider_than_screen Duplicate Contentcontent.duplicate_exact

Warnings (57)

Rate Limited (429)response.rate_limited Slow Responseresponse.slow Redirect Chainredirect.chain Temporary Redirect (302/307)redirect.temp_internal Meta Refresh Redirectredirect.meta_refresh Mixed Contenthttp.mixed_content Insecure URLhttp.http_url Duplicate Titletitle.duplicate Title Too Longtitle.too_long Multiple Titlestitle.multiple Missing Meta Descriptionmeta_desc.missing Duplicate Meta Descriptionmeta_desc.duplicate Meta Description Too Longmeta_desc.too_long Multiple Meta Descriptionsmeta_desc.multiple Missing H1h1.missing Multiple H1sh1.multiple Canonical Chaincanonical.chain Canonical Contains Fragmentcanonical.fragment Relative Canonicalcanonical.relative Canonical Outside Crawlcanonical.outside_crawl Noindexindex.noindex Nofollow Pageindex.nofollow_page Blocked by robots.txt but Linkedindex.blocked_robots Sitemap Orphansitemap.orphan Sitemap Over 50,000 URLssitemap.too_many_urls Orphan Pagelink.orphan Links to Broken External URLlink.broken_external Page Without Internal Outlinkslink.no_internal_outlinks Images Missing Alt Textimage.missing_alt Soft 404content.soft_404 hreflang to Non-Indexable URLhreflang.non_canonical_target Missing Self-Referencing hreflanghreflang.missing_self Inconsistent Language & Region Return Linkshreflang.inconsistent_return Multiple hreflang Entries for One Languagehreflang.multiple_entries Non-ASCII Characters in URLurl.non_ascii Space in URLurl.space Internal Search URLurl.internal_search Tracking Parameters in URLurl.tracking_parameters Double Slash in URLurl.multiple_slashes Missing Viewportmobile.missing_viewport Unsafe Cross-Origin Linkssecurity.unsafe_cross_origin_links HTML Document Over 15 MBvalidation.document_too_large Title Updated by JavaScriptjs.title_changed Content Only in Rendered HTMLjs.content_only_rendered Links Only in Rendered HTMLjs.links_only_rendered Pages with JavaScript Errorsjs.errors Redirection (JavaScript)js.redirect Rendering Failedjs.render_failed Unlinked Pagination URLpagination.unlinked Non-Indexable Paginated Pagepagination.non_indexable Multiple rel=nextpagination.multiple AMP Page Not Linked From Its Canonicalamp.missing_return_link AMP Page With Non-Indexable Canonicalamp.non_indexable_canonical Accessibility: Serious Violationsa11y.serious Text Too Small To Readmobile.small_text Tap Targets Too Small Or Too Closemobile.tap_targets Near Duplicate Contentcontent.near_duplicate

Opportunitys (39)

Title Too Shorttitle.too_short Title Same as H1title.same_as_h1 Meta Description Too Shortmeta_desc.too_short Duplicate H1h1.duplicate Non-Sequential Headingsheading.skip_level No Subheadingsh2.missing Missing Canonicalcanonical.missing URL in Multiple Sitemapssitemap.multiple Indexable URL Not in Sitemapsitemap.missing_indexable Deep Pagelink.deep Internal Nofollow Linklink.internal_nofollow Empty Anchor Textlink.empty_anchor Generic Anchor Textlink.generic_anchor Non-Indexable Page Inlinks Onlylink.non_indexable_inlinks_only Too Many Linkslink.too_many Images With Empty Alt Textimage.empty_alt Alt Text Over 100 Charactersimage.alt_too_long Images Missing Size Attributesimage.missing_size Large Imageimage.large Thin Contentcontent.thin Low Text-to-HTML Ratiocontent.low_text_ratio Readability Very Difficultcontent.readability_difficult Spelling Errorscontent.spelling Grammar Issuescontent.grammar Unlinked hreflang URLhreflang.unlinked_target Missing x-defaulthreflang.missing_xdefault Uppercase in URLurl.uppercase Underscore in URLurl.underscore URL with Parametersurl.parameters URL Too Longurl.too_long Repetitive Pathurl.repetitive_path No Structured Dataschema.missing Structured Data Validation Warningsschema.validation_warning Missing X-Content-Type-Options Headersecurity.missing_x_content_type_options Missing X-Frame-Options Headersecurity.missing_x_frame_options Missing Content-Security-Policy Headersecurity.missing_csp Missing Referrer-Policy Headersecurity.missing_referrer_policy Missing HSTS Headersecurity.missing_hsts Accessibility: Moderate & Minor Violationsa11y.moderate_minor