On-Page SEO Checker – Instant Checklist for Any Public URL

Every page we audit for a client goes through the same checklist; title tag length, meta description presence, H1 consistency, heading hierarchy, canonical setup, OG tags, structured data, image alt text. We built this tool to run that checklist automatically on any public URL in seconds, so you can spot the most common technical on-page issues without opening a browser console or paying for a full audit tool.

What gets checked and why it matters

Title tag: checked for presence, character length (target: 50-60 characters), and whether it differs from the H1. The title tag is the strongest on-page ranking signal and the primary text shown in search results.

Meta description: checked for presence and length (target: 120-155 characters). Google rewrites meta descriptions frequently, but having an accurate, well-written one still influences click-through rates and is the fallback when Google can’t find a better snippet.

H1 tag: checked for presence (is there one?) and uniqueness (is there only one?). Every page should have exactly one H1. Multiple H1s confuse heading hierarchy; missing H1s waste a strong topical signal.

Heading hierarchy: checks whether headings follow a logical sequence (H1 → H2 → H3) without skipping levels. Skipped heading levels (H1 directly to H4) indicate structural issues that can also cause accessibility failures.

Word count: pages under ~300 words are at risk of being classified as “thin content” by Google. This doesn’t mean every page needs 2,000 words, it means the content needs to adequately cover the topic relative to what’s ranking.

Readability score: the Flesch Reading Ease score for the body text. Not a direct ranking signal, but content that’s genuinely hard to read tends to have higher bounce rates and lower engagement, both indirect signals Google measures.

Canonical tag: checks whether a canonical tag is present and whether it points to the page’s own URL (self-referencing canonical). Missing or incorrect canonicals cause duplicate content issues, especially on paginated pages and filtered e-commerce categories.

Open Graph tags: verifies presence of og:title, og:description, og:image. Missing OG tags mean broken or generic link previews when the page is shared on social media.

JSON-LD schema: checks whether any structured data block is present on the page. Not validated for accuracy, just presence.

Image alt text: spot-checks the first several images on the page for missing alt attributes. Missing alt text is both an accessibility failure and a missed opportunity for image search ranking.

How to use results from this tool

The output is a scored checklist, not a ranking prediction. Use it to identify the highest-priority fixes on a specific page, start with the red (fail) items, then the yellow (warnings). A page that passes all checks isn’t guaranteed to rank; a page that fails several is leaving clear improvement opportunities untouched.

FAQ

• Does passing all checks mean my page will rank well? No. The checklist covers technical on-page fundamentals, necessary conditions for good ranking, not sufficient ones. Content quality, topical authority, backlink profile, page speed, and user engagement signals all contribute to ranking. Think of passing this checklist as clearing the floor, not reaching the ceiling.
• Why does the tool check for only one H1? Having multiple H1 tags on a page isn’t an automatic ranking penalty, but it’s a structural signal that the page may not have a clear primary topic. A page with three H1 tags gives Google less clarity about what the page is fundamentally about compared to a page with one H1 and well-organized H2/H3 subheadings. Most modern SEO guidance recommends one H1 per page.
• What word count should my page target? There is no universal correct word count, it depends on the query. For informational blog posts competing with comprehensive guides, 1,500-2,500 words is typical. For local service pages (a dentist in Salt Lake City), 400–800 focused words can outperform longer pages if the content is more relevant. The right benchmark is what’s already ranking for your target keyword, not a fixed number.
• The tool checks for schema presence, does it validate the schema? No, it detects whether a JSON-LD block exists on the page, not whether it’s valid or complete. Use Google’s Rich Results Test (search.google.com/test/rich-results) for schema validation. The presence check here is a quick signal; pages with no schema at all are missing one of the most available technical SEO opportunities.
• Can I check pages that require a login or are behind a password? No. The tool fetches publicly accessible URLs only. Pages behind authentication, Basic Auth, or IP restrictions will return an error or empty results. For protected pages, use browser developer tools or a local audit instead.

A checklist shows you what to fix, but fixing technical SEO issues across a whole site, prioritizing them correctly, and connecting them to a content strategy takes more than a tool. We do full SEO audits and ongoing SEO management for small businesses.