
Google recommends ” use different URLs for different language versions “.
Instead of using the URL http://www.abc.co.jp/ in both English and Japanese
Japanese: http://www.abc.co.jp/
English: http://www.abc.co.jp/en/
or
Japanese: http://www.abc.co.jp/
English: Different URLs such as http://en.abc.co.jp/ are desirable, and it is not recommended to include both Japanese and English on one page. In this way, we will explain the problems and solutions that can occur if you have different URLs for each language.
Possible problems when creating a multilingual website
If you create your website in multiple languages, there are three possible problems.
1. I have a website that specializes in a specific language, but the search results show sites in different languages . For example, a website with a currency written in American English of $ is displayed even though there is a page with a currency written in British English of £.
2. If there are multilingual sites, both will be displayed, which will confuse the user.
3. Google is unaware that a new language site has been created .
You can avoid this problem by letting Google know that the page has a different language version using rel = ”alternate” hreflang.
hreflang annotation 3 ways
HTML tags
Add within the page to let Google know all versions of the page by language and region.
lang_code
Language and region code for this page
url_of_page
Page URL for the specified language or region
If you have versions for 4 different languages / regions, as in the slide below, write rel = “alternate” hreflang for 4 pages (ie including yourself) . hreflang works by linking each other to each other’s version. (To prevent unauthorized use from other sites). Be sure to write a link to your version as well.

Language / region designation
The value of hreflang is
Language: Specified in ISO 639-1 format
Region (if required): Specified in ISO 3166-1 Alpha 2 format
(example)
de: German content, no region specified
en-GB: English content for UK users
de-ES: German content for Spanish users
HTTP header
Notify Google by returning a header in the following format:
Link :; rel = “alternate”; hreflang = “lang_code_1”,; rel = “alternate”; hreflang = “lang_code_2”, …
URL corresponding to the language or region specified in hreflang
lang_code_x
Language or region code targeted by this version of the page
XML Sitemap
Use a sitemap to let Google know the language and regional version of each URL. Below is a Sitemap sample in the Search Console Help.
www.example.com/english/page.html –For English-speaking users
www.example.com/deutsch/page.html –For German-speaking users
www.example.com/schweiz-deutsch/page.html –For German-speaking Swiss users
http://www.example.com/english/page.html
http://www.example.com/deutsch/page.html
http://www.example.com/schweiz-deutsch/page.html
Benefits of hreflang annotations
Can correctly inform search engines of multilingual structure
When you create a site in a new language, you can reliably convey the new page by writing hreflang on the page that is already indexed.
Can display sites in the appropriate language when users search