SEOInfo is a browser extension that checks your website for SEO-related issues. With it, you can find and check for common problems, like the Hreflang tag on a page or the right AMP version. It also displays performance data and full AMP status and errors for HTML pages. SEOInfo will alert you as you navigate your website for SEO issues.

It's free, secure, and available in four languages (English, Spanish, Russian, and French). It's available for Windows and Mac and is compatible with Chrome and Firefox.