SEO Medium impact Hard demanding setup

Hreflang (multilingual sites)

Tells Google which language version belongs to which audience.

What it is

Hreflang is markup that, on a multilingual/multi-country site, specifies which language and regional version of a page exists (e.g. cs, sk, en-us).

Why it matters

Without hreflang, Google may show the wrong language version or treat versions as duplicates. Correct hreflang ensures a Czech user sees the Czech version and a Slovak user the Slovak one.

How to do it

1For each version, add hreflang links to all other versions and to itself (self).
2Use correct language (and where applicable, country) codes: cs, sk, en-us…
3Add x-default for the default version.
4Hreflang must be reciprocal (A references B and B references A) and point to canonical URLs.

Example

Correct

<link rel="alternate" hreflang="cs" href="https://example.cz/">
<link rel="alternate" hreflang="sk" href="https://example.sk/">
<link rel="alternate" hreflang="x-default" href="https://example.cz/">

Conclusion

Only deal with hreflang on genuinely multilingual/multi-country sites, but there it's crucial and easy to get wrong (it must be reciprocal and complete). A monolingual site doesn't need it. After deployment, verify in Search Console.