Daylytix runs 150+ individual checks across 9 categories every time you audit a site. Each check is assigned a severity level — Critical, Warning, or Notice — that contributes to your overall audit score and determines where the issue appears in reports.
Severity levels: Critical issues directly harm rankings or user experience and should be fixed immediately. Warning issues represent best-practice gaps. Notice items are informational — worth reviewing, but not urgent.
Technical SEO
Technical checks examine the infrastructure of your site — how it is structured, indexed, and navigated by search engine bots.
| Check | Severity | What it detects |
|---|---|---|
| Missing canonical tag | Warning | Pages with no rel="canonical" link, leaving indexation ambiguous for search engines. |
| Self-referencing canonical | Notice | Canonical points to the same URL — correct, but flagged to confirm intent. |
| Canonical pointing to redirect | Critical | The canonical URL returns a 301/302 redirect instead of the final destination page. |
| Redirect chains (3+ hops) | Critical | URLs that pass through 3 or more redirects before reaching the final page, wasting crawl budget and link equity. |
| Redirect loops | Critical | A URL redirects back to itself or creates a circular chain that never resolves. |
| Hreflang errors | Critical | Missing return tags, invalid language codes, or hreflang pointing to redirected/broken URLs. |
| robots.txt unreachable | Warning | The robots.txt file returns a non-200 status code, which search engines interpret as "no restrictions". |
| Sitemap missing | Warning | No XML sitemap found at /sitemap.xml or declared in robots.txt. |
| Sitemap contains redirected URLs | Warning | URLs listed in the sitemap that return a redirect instead of 200. |
| Sitemap contains 4xx URLs | Critical | Broken pages listed in the sitemap — tells search engines to crawl pages that don't exist. |
| Trailing slash inconsistency | Warning | The same page is accessible with and without a trailing slash, creating duplicate content risk. |
| Soft-404 pages | Warning | Pages returning HTTP 200 but displaying "not found" content or containing fewer than 50 words. |
| Broken internal links (4xx) | Critical | Internal links pointing to pages that return a 404 or other client error. |
| Broken external links | Warning | Outbound links to external pages that return errors. Hurts credibility and user experience. |
| Pages blocked by robots.txt | Notice | Internal pages disallowed in robots.txt — flagged to confirm the block is intentional. |
| Noindex on important pages | Critical | Pages with noindex directives that appear to be content pages (not thank-you or admin pages). |
Performance
Performance checks use Google PageSpeed Insights data for both mobile and desktop. Core Web Vitals thresholds match Google's current "Good" definitions.
| Check | Severity | What it detects |
|---|---|---|
| LCP > 4s (mobile) | Critical | Largest Contentful Paint exceeds 4 seconds on mobile — a direct ranking signal in Google's CWV assessment. |
| LCP 2.5–4s (mobile) | Warning | LCP is in the "Needs Improvement" range. Optimisation recommended. |
| CLS > 0.25 | Critical | Cumulative Layout Shift is high — content jumps visibly as the page loads, harming UX and rankings. |
| CLS 0.1–0.25 | Warning | CLS in the "Needs Improvement" band. |
| FID / INP > 500ms | Critical | Interaction to Next Paint is critically slow — the page feels unresponsive to user input. |
| FCP > 3s | Warning | First Contentful Paint is slow — users see a blank page for too long before any content appears. |
| TTFB > 600ms | Warning | Server response is slow before any content is delivered. May indicate hosting or server-side issues. |
| Mobile score < 50 | Critical | PageSpeed Insights mobile performance score is in the "Poor" range. |
| Mobile score 50–89 | Warning | Mobile performance score is in the "Needs Improvement" range. |
| Render-blocking resources | Warning | JavaScript or CSS files loaded synchronously in <head> that block rendering. Lists specific files. |
| Images not lazy-loaded | Notice | Below-the-fold images lacking loading="lazy" attributes. |
| Oversized images | Warning | Images served at a resolution much larger than their displayed size, wasting bandwidth. |
| Images in legacy formats | Notice | JPEG/PNG images that could be served in WebP or AVIF for significant size savings. |
| Missing compression (gzip/br) | Warning | Server does not compress HTML/CSS/JS responses, increasing transfer sizes unnecessarily. |
| Missing cache headers | Notice | Static assets served without appropriate Cache-Control headers. |
On-Page SEO
On-page checks inspect the content and metadata of each crawled page to ensure best practices for search visibility.
| Check | Severity | What it detects |
|---|---|---|
| Missing title tag | Critical | Page has no <title> element. Search engines will generate one automatically, often poorly. |
| Duplicate title tags | Critical | Multiple pages sharing the same title — confuses search engines about which page to rank. |
| Title too long (>60 chars) | Warning | Title is likely to be truncated in search results, reducing click-through appeal. |
| Title too short (<20 chars) | Notice | Very short titles may not convey enough context to rank competitively. |
| Missing meta description | Warning | No meta description — search engines will generate a snippet from page content, often less compelling. |
| Duplicate meta descriptions | Warning | Multiple pages with identical meta descriptions, reducing snippet variety in search results. |
| Meta description too long (>160 chars) | Notice | Descriptions that will be truncated in search result snippets. |
| Missing H1 | Critical | Page has no H1 heading — a primary on-page relevance signal for search engines. |
| Multiple H1 tags | Warning | More than one H1 on a single page — dilutes the primary topic signal. |
| Heading hierarchy violations | Warning | Heading levels skipped (e.g. H1 directly followed by H4), breaking document structure. |
| Thin content (<100 words) | Warning | Pages with very little text content that are unlikely to rank well for informational queries. |
| Duplicate content | Critical | Pages with near-identical or very similar content — detected by content fingerprint comparison. |
Security
Security checks examine HTTPS configuration and the presence of important HTTP security headers.
| Check | Severity | What it detects |
|---|---|---|
| No HTTPS redirect | Critical | HTTP version of the site does not redirect to HTTPS — users can access the site insecurely. |
| SSL certificate expired or invalid | Critical | The SSL certificate is expired, self-signed, or does not match the domain. |
| Mixed content | Critical | HTTPS pages loading resources (images, scripts, iframes) over insecure HTTP. |
| Missing HSTS header | Warning | No Strict-Transport-Security header, making the site vulnerable to SSL-stripping attacks. |
| Missing Content-Security-Policy | Warning | No CSP header configured to restrict resource loading origins. |
| Missing X-Frame-Options | Warning | Pages can be embedded in iframes on other sites, enabling clickjacking attacks. |
| Missing X-Content-Type-Options | Notice | No nosniff directive, allowing browsers to MIME-type sniff responses. |
| Insecure forms | Critical | Forms on HTTPS pages that submit data to HTTP endpoints. |
Accessibility
Accessibility checks examine how usable your site is for visitors using assistive technologies. A score from 0–100 is calculated based on the volume and type of issues found.
| Check | Severity | What it detects |
|---|---|---|
| Images without alt text | Critical | Non-decorative images missing alt attributes — screen readers cannot convey image content. |
| Empty anchor tags | Warning | Links with no visible text or accessible name — screen readers announce "link" with no destination context. |
| Generic link text | Warning | Links using phrases like "click here", "read more", or "learn more" with no additional context. |
| Form inputs without labels | Critical | Form fields lacking associated <label> elements or aria-label attributes. |
| Heading hierarchy violations | Warning | Heading levels that skip ranks (e.g. H2 to H4), breaking the document outline for screen readers. |
| Pages with no H1 | Warning | Pages lacking a primary heading, making it difficult for screen reader users to understand the page topic. |
| Pages with multiple H1s | Notice | Multiple H1 headings per page break the expected document hierarchy. |
Content Quality
Content checks go beyond simple word counts to evaluate the depth, freshness, and uniqueness of your site's pages.
| Check | Severity | What it detects |
|---|---|---|
| Thin pages (<100 words) | Warning | Pages with very little substantive content, unlikely to satisfy search intent. |
| Content decay | Warning | Pages that previously drove significant GSC clicks but have seen consistent decline — identified using historical comparison. |
| Boilerplate content | Notice | Pages whose body text is nearly identical to other pages (template pages with little unique content). |
| Near-duplicate titles | Warning | Titles that are slightly different but semantically identical, diluting topical signal. |
| Missing Open Graph tags | Notice | Pages lacking OG meta tags — social shares will show unformatted previews. |
| Missing Twitter Card tags | Notice | Pages lacking Twitter Card meta — Twitter/X shares will not show rich previews. |
Links & Internal Linking
| Check | Severity | What it detects |
|---|---|---|
| Broken internal links | Critical | Internal <a> links returning 4xx or 5xx status codes. |
| Broken external links | Warning | Outbound links to external pages that are unreachable or deleted. |
| Orphan pages | Warning | Pages discovered via sitemap or other means that receive zero internal links — invisible to crawlers following links. |
| Underlinked pages | Notice | Pages receiving far fewer internal links than the site average, reducing their crawlability and authority. |
| Redirect chains in internal links | Warning | Internal links that point to URLs which redirect rather than the final canonical URL. |
| Nofollow on internal links | Notice | Internal links tagged rel="nofollow", blocking PageRank flow between your own pages. |
Structured Data
| Check | Severity | What it detects |
|---|---|---|
| Missing schema markup | Warning | Pages that would benefit from structured data (blog posts, products, FAQs, local businesses) but have none. |
| Invalid JSON-LD syntax | Critical | Schema blocks that cannot be parsed due to malformed JSON. |
| Missing required schema properties | Warning | Schema present but lacking required fields (e.g. Product without name or offers). |
| Schema type mismatch | Notice | The schema type declared does not match the detected page type (e.g. Article schema on a product page). |
| No FAQ schema on FAQ pages | Warning | Pages containing Q&A content (3+ question/answer pairs) with no FAQPage schema to enable rich results. |
AI Schema generation: Daylytix can automatically generate correct, ready-to-paste JSON-LD schema markup for any page using the AI Schema tool. See AI Schema generator for details.