# hreflang alternates

Canonical HTML: /atlas/hreflang
Atlas version: atlas-2026-07-28-v1
Category: Crawler and indexing directives

## Definition

hreflang annotations connect language or regional variants of substantially equivalent content.

## How it works

Each variant names itself and its alternates using valid language-region codes, often with an optional x-default fallback.

## How to validate it

Verify reciprocal annotations, canonical consistency, return status, and exact URL normalization across every member of the alternate set.

## Common failure

Pointing every localized page at one canonical language can undermine the alternate cluster the hreflang annotations were meant to describe.

## Related topics

- [Canonical links](/atlas/canonical-links)
- [Sitemap discovery](/atlas/sitemap-discovery)