Hreflang Tag Generator & Validator

Hreflang is one of the easiest SEO signals to get technically wrong while looking completely fine, a single broken reciprocal link between two language versions can quietly undermine international targeting for months. This tool generates correct hreflang tags for a set of language and region variants, and validates existing tags for the specific errors that actually cause problems, including checking whether alternate pages link back correctly, not just whether tags are present.

Why return tags are the whole game

Hreflang isn't a one-directional hint, it's a mutual confirmation. If a Spanish page says its English version lives at a certain URL, that English page has to say the Spanish version lives back at the original URL, or the relationship isn't considered valid. This is, by a wide margin, the most common real-world hreflang failure, one page in a set gets updated, redirected, or rebuilt, and the reciprocal link silently breaks while every tag involved still looks syntactically correct. Checking for this requires actually visiting the alternate pages and reading their own tags, which is why this tool includes a dedicated check that fetches each alternate URL and confirms it really does link back.

x-default, and why it's worth including

x-default marks a fallback page to show a visitor whose language or region doesn't match any of the specific variants in the set, a French visitor arriving at a site with only English and Spanish versions, for example. It's optional, not every hreflang set needs one, but leaving it out means that ambiguous case is left entirely to a search engine's own judgment rather than an explicit choice. The generator here treats it as its own distinct option per URL, disabling the language and region fields for that row since x-default is a standalone marker, not a language-region pair.

Two valid ways to implement hreflang

Hreflang can be declared as link tags in each page's own HTML head, or as xhtml:link attributes inside an XML sitemap covering the whole set at once, both are equally valid and search engines treat them the same way. The sitemap approach can be easier to maintain for a large site, since the relationships live in one file rather than being duplicated across every page's head, while the HTML approach is simpler for a small number of pages. This tool generates a complete, valid version of either, including the correct xhtml namespace declaration the sitemap format requires.

What the return-tag check can't cover

Checking return tags means fetching every alternate page individually, which takes real time and is capped at 20 alternates per check to keep it from running indefinitely on an unusually large set, a page with more variants than that will only have its first 20 checked, clearly noted when it happens. A page that blocks automated requests, sits behind authentication, or simply times out will show as unable to be checked rather than as passing or failing, since that's genuinely a different situation from a confirmed broken link.

Runs mostly in your browser

Generating and validating tags from HTML you paste in happens entirely locally. Fetching a URL, and checking return tags on its alternates, does route through this site to retrieve each page's content, since a browser can't otherwise read another site's raw HTML directly. Since hreflang sets and a site's canonical tags need to agree with each other, our Canonical Tag Checker and XML Sitemap Validator are worth checking too, both part of the same Technical SEO collection this tool belongs to.