Insights · Technical setup for Japan
hreflang for a Japanese version: ja or ja-JP, what the tags must do, and the three mistakes we keep finding
hreflang is the smallest piece of a Japanese launch and the one most often done in a way that does nothing. The rules fit on one page. The mistakes are the same three, over and over.
Published 2 September 2026. Requirements from Google Search Central documentation on localized versions and on multi-regional sites, confirmed 2 September 2026. The example is SuzuLabo's own site.
What hreflang is for, in one paragraph
When a site has the same page in more than one language or for more than one region, hreflang tells Google which version belongs to which audience, so that a Japanese searcher is shown the Japanese page rather than the English one. Google's documentation puts it this way: "If you have multiple versions of a page for different languages or regions, tell Google about these different variations." It also notes that Google may find the versions on its own without it; hreflang is the way to remove the guesswork.
It is not a ranking signal. A correct hreflang set does not make the Japanese page rank higher; it makes the right version appear when the page ranks at all. That distinction is why it is worth doing correctly and not worth agonizing over.
ja or ja-JP
| You write | What it means | Use it when |
|---|---|---|
hreflang="ja" | Japanese, any region | The page is for Japanese readers wherever they are. The safe default. |
hreflang="ja-JP" | Japanese, for Japan | You also serve Japanese readers elsewhere with a different page, or you want the country stated. Otherwise it adds nothing over ja. |
hreflang="jp" | Not valid | Never. "jp" is a country code, not a language code, and the country code cannot be used alone. The annotation is ignored. |
hreflang="en" | English, any region | Your English page, in the same set. |
hreflang="x-default" | Fallback for unmatched languages | A language selector or the page you want shown when nothing matches. |
Language codes must be ISO 639-1 and region codes ISO 3166-1 Alpha 2, per Google Search Central, "Tell Google about localized versions of your page", confirmed 2 September 2026.
For almost every foreign company with one Japanese version, ja is enough. You add the region only when you have two Japanese versions for different places, which is rare, or when the country is the point of the page. What you must not do is invent a code: jp, japanese and ja_jp with an underscore all fail silently. Google's page is explicit that only ISO 639-1 language codes and ISO 3166-1 Alpha 2 region codes are supported, and that a country code cannot be used by itself.
What the set must do
- Every version links to every version, including itself. The English page lists the Japanese URL and its own; the Japanese page lists the English URL and its own. Google's troubleshooting section names the missing return link as the most common mistake: "If page X links to page Y, page Y must link back to page X."
- Absolute URLs. The full
https://address, not a relative path. - A fallback when it helps.
x-defaultfor a language selector or the page you want shown to everyone else. Optional, and often skipped on a two-language site. - One place, consistently. HTML
<link>elements in the head, or the sitemap, or HTTP headers for non-HTML files. Mixing is allowed; contradicting is not.
That is the whole specification as it applies to a Japanese version. Everything else on the topic is either a tool or a mistake.
The three mistakes that disable it
The canonical conflict deserves a sentence more. If the Japanese page carries rel="canonical" pointing at the English page, you have told Google the Japanese page is a duplicate and should not be indexed on its own. hreflang cannot override that. It happens when a template sets the canonical from a site-wide default and the Japanese section inherits it. Fix the canonical first; then hreflang has something to work with.
How our own site does it
suzulabo.co.jp is a Japanese site with an English section. The Japanese home page carries two annotations: hreflang="ja-JP" pointing to itself and hreflang="en" pointing to /en/. The English home page carries the same pair in reverse. Each English article and service page below /en/ carries a self-referencing hreflang="en" and a self-referencing canonical, and no Japanese counterpart, because there is no Japanese twin of those pages; a set of one is harmless and mainly documents intent.
We use ja-JP rather than ja on the Japanese home page because the company is in Japan and the page is for Japan, and because the site is a ccTLD anyway. Either would have worked. What matters more, and what we check on every deployment, is that the two home pages still point at each other after any template change, and that no English page has picked up a canonical to a Japanese URL. Those two checks are in the ten-point list in our self-run Japan site audit.
FAQ
Frequently asked questions
Should I use ja or ja-JP for a Japanese version?
ja is enough for one Japanese version. ja-JP states the country as well; use it if you serve Japanese readers elsewhere with a different page, or if you simply want the country explicit. jp on its own is invalid.
Does hreflang help the Japanese page rank?
No. It helps the right language version be shown when a page ranks. Ranking still depends on the content, links and technical health of the Japanese page itself.
Do I need x-default on a two-language site?
It is optional. It is most useful when you have a language selector or auto-redirecting home page. Many two-language sites skip it without harm.
Can I put hreflang in the sitemap instead of the pages?
Yes. Google accepts HTML link elements, sitemap annotations, or HTTP headers. Use one method consistently and make sure the return links are complete in whichever you choose.
My Japanese page and English page are on different domains. Does that work?
Yes, hreflang works across domains as long as every version links to every version with absolute URLs. Cross-domain sets are simply easier to break when one side is edited alone.
How do I check whether Google accepted the set?
Search Console does not report hreflang errors in a dedicated report today. Check the page source of both versions, confirm the return links, and confirm the canonical on each page points to itself.
If you would rather have the set checked than trust it
Send the English and Japanese URLs. We will reply in writing with whether the annotations, canonicals and language declarations agree with each other, and what to change if they do not. That reply is free.