Paste the address of any page on your site. We read it the way Google does and check hreflang, lang, canonical and each translated version, with a clear fix for every problem.
What this checker looks at
hreflang tags in the <head> and in the HTTP Link header: valid codes, absolute URLs, self-reference, x-default and duplicates.
The lang attribute of <html>, and whether it matches the language each hreflang announces.
The canonical tag: one that points to another language makes Google ignore your hreflang.
Up to 6 translated versions: they load, link back, declare their language and really are translated.
Title, meta description, og:locale, noindex and your URL structure per language.
Tools that only translate in the browser with JavaScript, which Google often doesn't see.