What is hreflang?
Hreflang は、Web ページの対象となる視聴者の言語と場所を指定する HTML 属性です。
The hreflang attribute is mostly used by sites that publish in multiple languages or have content targeted at audiences within a geographic location.
Using the hreflang attribute, search engines like Google can determine the appropriate content to show the visitor depending on their language and location.
You can specify the hreflang attribute using the two-letter ISO 639-1 language code. For example, en for English and fr for French.
You can also specify it using the two-letter ISO 639-1 language code, a hyphen, and then the two-letter ISO 3166-1 alpha-2 country code. For example, en-US for English targeted at the US and fr-CA for French targeted at Canada.
The hreflang attribute is declared in a URL, as shown below.
<link rel=”alternate” href="https://www.yourdomain.com" hreflang="en-us" />