SEO validation rules
20 rules. Each with thresholds, edge cases, and configuration. Critical rules block CI builds. Optional rules reduce your score.
Critical rules
— block CI builds on errortitle-present
The title tag is the single most important on-page SEO element. It appears in browser tabs, search results, and social s...
description-present
The meta description is your page's sales pitch in search results. Without one, Google auto-generates a snippet from you...
og-image
When someone shares your page on Twitter, LinkedIn, Slack, or Discord, the og:image is the large visual preview that mak...
canonical-url
The canonical URL tells search engines which version of a page is the 'original.' Without it, Google may index /page, /p...
h1-present
The H1 is your page's primary heading — the strongest on-page signal for its main topic. Search engines use it alongside...
Optional rules
— reduce your scoretitle-length
Google displays approximately 50-60 characters of your title tag in search results (or about 580 pixels wide). Titles th...
description-length
Google displays roughly 155-160 characters of your meta description in desktop search results (less on mobile). Descript...
og-title
When og:title is absent, social platforms fall back to your HTML <title> tag. The problem: HTML titles often include bra...
og-description
The og:description appears as the subtitle text under your link title in social shares. Without it, platforms either use...
structured-data-present
Structured data (JSON-LD) tells search engines exactly what your page contains in a machine-readable format. Without it,...
structured-data-valid
Having JSON-LD on your page is necessary but not sufficient. If it lacks the required @context and @type fields, search ...
structured-data-complete
Different schema types have different required fields. An Article without a headline, a Product without a name, a FAQ wi...
structured-data-duplicates
Some schema types should only appear once per page. Two FAQPage blocks, two BreadcrumbList blocks, or two Organization b...
content-length
Thin content pages provide little value to users and rank poorly. Google's Helpful Content system specifically penalizes...
robots-not-blocking
A noindex meta robots directive tells Google to never show this page in search results. If it's intentional (thank-you p...
twitter-card
The twitter:card meta tag controls how your link appears when shared on X (formerly Twitter). Without it, your link show...
alternates-hreflang
Hreflang tags tell search engines about the language and regional targeting of your pages. If you have multiple language...
viewport-meta
The viewport meta tag controls how your page renders on mobile devices. Without it, mobile browsers render the page at a...
favicon
A favicon is the small icon in your browser tab, bookmarks bar, and mobile home screen. Without one, browsers show a gen...
image-alt-text
Alt text is the text description of an image for screen readers and search engines. Without it, visually impaired users ...