CrawluneTechnical SEO checks
Crawlune runs 165 checks on every crawl. Each one explains why it matters and how to fix it.
Response codes
- No responseerror
- Client error (4xx)error
- Server error (5xx)error
- Redirect looperror
- Redirect to error pageerror
- Redirect chainwarning
- Blocked by robots.txtwarning
- External link brokenwarning
- Slow response (over 2s)warning
- Content-Type header missingwarning
- Redirect (3xx)info
- Temporary redirect (302/303/307)info
URL
JavaScript
- Canonical changed by JavaScripterror
- Robots directive changed by JavaScripterror
- Page could not be renderedwarning
- Title changed by JavaScriptwarning
- Meta description changed by JavaScriptwarning
- Links only present after renderingwarning
- Content depends on JavaScriptwarning
- H1 changed by JavaScriptopportunity
Security
- HTTP URL (not HTTPS)error
- Mixed contenterror
- Form posts to HTTPerror
- Missing HSTS headeropportunity
- Missing X-Content-Type-Options headeropportunity
- Missing X-Frame-Options / CSP frame-ancestorsopportunity
- Unsafe cross-origin linksopportunity
- Missing Referrer-Policy headerinfo
- Missing Content-Security-Policy headerinfo
- Server version disclosedinfo
Page titles
Meta description
H1
Headings
Canonicals
Directives
Content
- Structured data is not valid JSONerror
- Soft 404error
- Near-duplicate contentwarning
- Structured data is missing required propertieswarning
- Exact duplicate contentwarning
- Lorem ipsum placeholderwarning
- Content before the doctypewarning
- Invalid element inside <head>warning
- Duplicate html, head or bodywarning
- Viewport meta tag missingwarning
- Semantic duplicatewarning
- Character encoding not declaredwarning
- Low word count (under 200)opportunity
- HTML lang attribute missingopportunity
- Doctype missingopportunity
- Off-topic for this siteopportunity
- Spelling or grammar mistakesopportunity
- HTML over 500 KBopportunity
- No structured datainfo
Images
Links
- Links to localhosterror
- Links to broken internal URLserror
- Page has no internal outlinkswarning
- No internal inlinks foundwarning
- High crawl depth (over 3 clicks)opportunity
- Over 300 outlinksopportunity
- Non-descriptive anchor textopportunity
- Links to redirecting URLsopportunity
- Internal nofollow linksinfo
- Links with no anchor textinfo
Sitemaps
Hreflang
- Invalid hreflang language codeerror
- Hreflang points to non-200 URLerror
- Hreflang missing return linkerror
- Conflicting hreflang entrieserror
- Hreflang href is not absoluteerror
- Hreflang missing self-referencewarning
- Hreflang points to a non-indexable pagewarning
- Page language disagrees with its hreflangwarning
- Hreflang on a canonicalised pagewarning
- Hreflang missing x-defaultopportunity