Google SEO Checker
Scans a page or site for on-page and technical SEO signals and returns a report of issues, warnings, and improvement suggestions.
If you have ever picked a keyword on a low score and still failed to rank, you already know the number is not the whole story.
Key points
- Treat the score as a diagnostic snapshot, not a ranking guarantee.
- Fix issues by traffic impact, not by report order.
- Run a check after every major change: migration, template update, or bulk publish.
- Log scores in a Google Sheets tracker to spot regressions early.
- Combine the checker with a broader audit of content quality and search performance.
The same page, three different scores
You run a product page through three free SEO checkers. One gives it 72, flags missing alt text and a slow Largest Contentful Paint. Another gives it 88, ignores the speed issue but warns about a thin meta description. The third gives it 61, penalises the same missing alt text twice and adds a warning about a low word count. All three are correct within their own logic. None of them tells you that the page ranks third for its main keyword because it has strong backlinks and a clear buying intent. The score is a filter, not a verdict.
Three things an SEO checker is not
- Not a ranking guarantee It estimates effort, not outcome. A low score can still be unwinnable if your page is thin, or a high score can rank poorly if competitors are stronger.
- Not a Google tool Most checkers are third-party diagnostics built on Lighthouse or vendor logic. They are not Google's ranking system and do not see the same data.
- Not a full audit A checker scans visible signals. A proper technical seo audit also reviews server logs, crawl budget, index coverage, and content quality.
Four ways it goes wrong
- Vendor-defined scoring Each tool sets its own thresholds and weights. A score of 80 in one tool may mean 60 in another. Compare scores only within the same tool when you check seo.
- Outdated criteria Core Web Vitals thresholds shift. A checker that does not update its logic may flag issues that no longer matter or miss new ones.
- Crawl vs. render gap A checker may crawl the raw HTML while Googlebot renders JavaScript. What the checker sees may differ from what Google processes, affecting crawlability assessments.
- No context on intent The tool cannot tell if a short page is perfect for a direct answer or if a slow page is acceptable for a high-value transaction.
Three checks before you act on a score
- Check the tool's data source Does it use Lighthouse, its own crawler, or an API? Each source has different coverage and accuracy for issues like page speed and mobile usability.
- Check the page's traffic Fix issues on pages that already get traffic first. A low-score page with zero visits is less urgent than a high-score page with declining traffic.
- Check for false positives Some warnings, like missing social meta tags, are harmless for ranking. Verify each issue against Google's own guidance before spending time on it.
Common questions
What is the best SEO checker?
There is no single best. Choose one that matches your stack: free tools for quick checks, paid tools for deeper audits and competitive analysis.
What is the best free SEO checker?
Google's own Lighthouse is free and authoritative. Yoast's SEO Checker and Semrush's free site audit are also solid options for on-page and technical signals.
What is the best SEO checker online?
Online checkers vary by scope. For a fast check, use a browser extension. For a full site scan, use a tool that can crawl multiple pages and export reports.
Sources
- Google Search Central Official guidance on crawling, indexing, and ranking signals
- Google Lighthouse Open-source tool for auditing performance, accessibility, and SEO
- Yoast SEO Checker Free on-page checker for title tags, meta descriptions, and readability
- Semrush Site Audit / Free SEO Checker Crawls up to 100 pages for technical and on-page issues