What does the free SEO checker test?
The SEO checker is a free tool from VirtuoLab that downloads one page and runs more than 30 checks in six categories. First, the meta category checks a title of 30 to 60 characters, a meta description of 120 to 160 characters, five Open Graph tags, Twitter Card tags and a canonical link. Second, the content category looks for exactly one h1, at least two h2 headings, alt text on every image, structured data and at least five internal links. Fewer than 300 words gets a warning, and the best result starts at 600. Third, the technical category checks the lang attribute, UTF-8, a favicon and the robots meta tag. According to Google, a noindex rule drops a page from search results. Finally, performance, mobile and security cover response time, compression, the viewport tag, HTTPS and five security headers. The checker does not run JavaScript, so a page built with React may show fewer words. For example, a site with 20 pages needs 20 runs.