SEO Tester

I use an SEO tester on every new page I publish. Before hitting publish, I drop the URL into a free checker and it usually catches two or three issues: a missing meta description, an h2 that skips a level, or an internal link pointing to a 404. That kind of feedback takes about 20 seconds and saves me from pushing out something broken. Most tools rank issues by severity, so I fix "critical" items first and leave warnings for when I have time. For a recent client blog, the tester flagged a canonical tag pointing to the wrong category page — a fix that took one minute but would have caused a duplicate content problem otherwise.

The speed of a page-level check is the killer feature. I can iterate on a title tag five times in a row, each check taking seconds. Over a year that probably saves me hours compared to running a full crawl every time. That said, I admit I used to think a single-page tester was enough to gauge site health. It took me a missed orphan pages issue on a client site to realise that testers only see what you put in front of them.

The biggest gap is full-site auditing. An SEO tester analyses one URL at a time, so it cannot detect crawl depth problems, orphan pages, or site-wide canonical issues. Last year I took on a site that looked clean on the homepage tester, but after running [Screaming Frog](/screaming-frog/) I found over 200 pages that no internal link reached. A tester would never have caught that. For site-level audits, you need a crawler that maps the entire architecture.

Performance diagnostics is another weak spot. Many SEO testers check page size or image compression, but they do not replace [Website Speed Test](/website-speed-test/) or Lighthouse for Core Web Vitals. I ran a tester that gave a passing score for a page that later failed LCP on real user data. The tester had checked static assets but missed render-blocking resources. So I now pair testers with dedicated performance tools.

Also, the recent trend of claiming "AI readiness" or "GEO score" feels like marketing fluff. I tested a tool that claimed to analyse AI visibility; it just checked for FAQ schema and word count. That is not a real signal. If you need competitor analysis or keyword gap identification, a simple SEO tester is the wrong tool — you want [Semrush](/semrush/) or [Ahrefs](/ahrefs/) for that.

For full-site technical audits, Screaming Frog is my go-to. Its free version crawls up to 500 URLs and reports on every standard SEO element, plus it integrates with Google Analytics for custom metrics. I use it at least once a month on every active site.

For ongoing monitoring, Semrush Site Audit prioritises issues by severity and tracks changes over time. I run it weekly on client sites to see if new pages introduce problems. Ahrefs offers a similar audit tool with a different UI — I switch between them depending on which subscription I have active that month.

If I need performance-focused analysis, I rely on Google Lighthouse and PageSpeed Insights rather than an SEO tester. They give specific actionable recommendations for speed.

For indexation and search behaviour, Google Search Console is irreplaceable. It shows which pages Google has indexed, which have errors, and how users find the site. I check it daily.

My rule of thumb: use a page-level tester for quick feedback during writing, a full-site crawler for weekly audits, and Search Console for ongoing site health. No single tool replaces the others.