How to fix hreflang tags with errors?

Fixing hreflang errors starts with identifying exactly what's wrong, which you can do using tools like Google Search Console's International Targeting report, or dedicated SEO tools like Ahrefs and Semrush that have specific hreflang auditing features designed to catch common mistakes across your entire site at once. The most frequent error is missing return tags, which happens when Page A references Page B as its alternate language version, but Page B doesn't reciprocally reference Page A back, since hreflang relationships need to be confirmed in both directions to work correctly, so you'll need to go through and ensure every page in a language cluster properly references every other page in that same cluster. Incorrect language or region codes are another extremely common issue, so double-check you're using proper ISO 639-1 language codes and ISO 3166-1 alpha-2 country codes rather than made-up or incorrect abbreviations, since even a small typo like using 'uk' instead of the correct 'gb' for United Kingdom will cause the tag to fail silently. Also make sure you've included a self-referencing hreflang tag on each page pointing to itself, and confirm that the URLs referenced in your hreflang tags are the canonical, indexable versions rather than redirected or blocked pages, since search engines will simply ignore hreflang tags pointing to inaccessible URLs.