日本語

Generate hreflang tags

The two mistakes that make search engines discard an hreflang set are a missing self-reference and a one-way link. This checks for both while you build it.

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How it works

  1. Add one line per language: code | URL.
  2. Choose which one x-default points to.
  3. Pick the output format and copy it.

Why nothing is uploaded

Every operation on this page is done by code running inside your browser tab, using the same engine that renders web pages. The file is read from disk into your tab’s memory, transformed there, and written back out as a download. It is never sent anywhere — not to us, not to a third party.

Verify it yourself

  1. Open your browser’s developer tools (F12) and select the Network tab.
  2. Load your file and run the tool.
  3. The only requests you will see are the tool’s own code and, once cached, none at all.

Proof it stays local →

Frequently asked questions

What is x-default for?

It names the page to show when none of your languages match the visitor — a language selector, or the international English version. It is optional, but without it the engine picks for you.

Region or language code?

Use the plain language code (ja, en) unless you genuinely have different content per country. en-GB and en-US only make sense if the pages differ in price, stock or spelling; splitting identical pages by region just divides the signal.

Does anything leave my browser?

No. There is no server behind this page doing the work and no API being called — the whole tool is JavaScript running in the tab. Load it once and it keeps working with the connection off.