The lang attribute

lang declares an element's content language using a BCP 47 code (e.g. uk, en, ru) — it affects screen reader pronunciation and auto-translation.

Applies to

global

Values

A BCP 47 language code: "uk", "en", "ru", "en-US", etc.

Example

<html lang="en">
<p lang="uk">Цей абзац українською.</p>

Edge cases

lang on <html> is required for correct screen reader behavior across the whole page, even if other elements don't set lang.
An incorrect lang causes screen readers to pronounce text with the wrong accent.

Accessibility

Without a correct lang, screen readers may pronounce text with the wrong engine accent.