og:locale: Set the Language of Your Open Graph Tags

og:locale declares the language and the region of the text in your Open Graph tags. The format is language_TERRITORY.

<meta property="og:locale" content="en_US" />

The default is en_US. If your page is in American English, the tag is optional. If your page is in another language, set it.

The format

Two lowercase letters for the language, an underscore, and two uppercase letters for the region: de_DE, pt_BR.
Use an underscore, not a hyphen. The HTML lang attribute uses en-US. Open Graph uses en_US. This is the most frequent mistake.
Always include the region. en alone is not valid.

Common og:locale values

Language	Value
English (United States)	`en_US`
English (United Kingdom)	`en_GB`
German	`de_DE`
French	`fr_FR`
Spanish (Spain)	`es_ES`
Spanish (Latin America)	`es_LA`
Portuguese (Brazil)	`pt_BR`
Italian	`it_IT`
Dutch	`nl_NL`
Japanese	`ja_JP`
Korean	`ko_KR`
Chinese (Simplified)	`zh_CN`

og:locale:alternate for translated pages

If the page exists in other languages, list them with og:locale:alternate. Use one tag for each language.

<meta property="og:locale" content="en_US" />
<meta property="og:locale:alternate" content="de_DE" />
<meta property="og:locale:alternate" content="fr_FR" />

og:locale and hreflang

They do different jobs. hreflang tells search engines which URL to show to a searcher in each language. og:locale tells social platforms the language of the preview text. A site with translations needs both.

og:locale in Next.js

export const metadata = {
  openGraph: {
    locale: 'en_US',
    alternateLocale: ['de_DE', 'fr_FR'],
  },
}

What happens when og:locale is missing

Platforms assume en_US. The preview still shows. For a page in German or Japanese, the wrong locale can affect how a platform formats and labels the share, so set the tag on each page that is not in American English.

Check a page with the Open Graph checker. Related: og:type, og:url, og:title, and the full list of Open Graph tags.