Japanese localization for Minecraft mods

くらふとぱれっと publishes free Japanese localization packs for Minecraft mods, alongside Japanese articles introducing each mod. The rest of the site is in Japanese, so this page explains the project in English.

It is an unofficial fan site, run by one person. Mod names and original texts remain the property of their authors. The packs contain translations only — never the mods themselves.

• •Send the mod JAR, or just the en_us.json language file if you would rather not hand over a build.
• •You get back a resource pack (.zip) containing the ja_jp.json language file and the build manifest. It drops into the resourcepacks folder and changes nothing about the mod itself.
• •If you would rather ship the Japanese inside your own mod, take the ja_jp.json on its own instead. It is the same file.
• •When your mod updates, send the new JAR. Strings whose English is unchanged are inherited from the translation memory, so only changed and new strings need work.
• •A single wrong line can be corrected and re-released on its own, without rebuilding anything else.
• •Forge, NeoForge and Fabric are all covered.

Cost and turnaround depend on the string count and on how much of it is prose rather than item and block names. Send the file and you get a concrete answer.

• •Minecraft mods and modpacks. That is where the evidence below comes from.
• •Other games, and software outside games: interface strings, in-app text, store listings, documentation, README files.
• •Key/value resource files of any format, and plain prose. Structured formats are preferred because the checks below apply to them.
• •Tooling and automation around localization: extraction, batching, machine checks, release steps.

• •326 localization packs, all free to download
• •312 of them translated from scratch — the mod shipped no Japanese, or only partial Japanese
• •182,269 translated strings, 1,069,147 words of English source text

25 short strings from 13 published packs, quoted as they ship. Where the Japanese deliberately departs from a literal reading, the reason is noted — run through a machine translator those lines will not round-trip, and that is the point.

Fifteen automated checks compare the English source against the Japanese output on every build. Two of them are hard failures: the build refuses to produce a pack, and there is no override flag.

• •Formatting arguments (%s, %1$d, and their type letters) must match the source in count, numbering and type. A mismatch throws a Java exception at runtime, which crashes the game.
• •Links inside guidebook text (item://, $(l:…), jei://) must stay ASCII. Japanese characters leaking into a link make the guidebook fail to resolve it.

The remaining thirteen are graded and feed a fix queue that is worked through monthly: lost formatting or colour codes (§a, $(br)), dropped line breaks, empty or placeholder output (TODO, ???), one Japanese string reused across many distinct English strings, the same English phrase rendered two different ways in the same context, translations far shorter or longer than their source, translated keys that no longer exist in the mod, half-width and full-width punctuation mixed within one pack, machine-translation tics, mod names transliterated into katakana with the plural s stranded, and Japanese conjugation errors.

Two further checks sit outside the per-build run:

• •Vanilla text is locked. Any string whose English exactly matches one of Mojang's 6,388 official entries is overwritten with the official Japanese at build time, whatever the translator wrote, so a mod cannot quietly rename something the base game already names. A separate audit re-checks that locked table against the official reference and fails if any entry has drifted away from it.
• •A monthly run re-scans the published packs, replays the same checks against them, and reports what has regressed since release.

The packs are produced by a command-line pipeline written for this project. It reads the mod JAR, extracts the language file, and resolves what it can without a human: locked vanilla terms first, then the translation memory for that mod, then the glossary, then structural patterns. Only what is left over goes to translation, and every result goes back into the memory.

Every pack the pipeline builds carries a manifest recording the SHA-1 of the JAR it was built from, its version, and the check results, so the pack can be traced back to the exact build it came from. A number of the older packs on the site were made before the pipeline existed and have no manifest; they are listed in a ledger the monthly run checks against, so the gap stays visible rather than quietly closing.

The pipeline has its own test suite, including a corpus of 407 verified translation pairs that has to keep passing whenever a rule changes.

Building that is what makes this volume maintainable by one person. If what you need is the tooling rather than the translation, that is the same work.

• Slag n' EmbersAug 10, 2026
• Smooth Scrolling ReforgedAug 10, 2026
• Exposure: ExpandedAug 10, 2026
• Ars ElixirumAug 5, 2026
• Dave's PotioneeringAug 5, 2026
• Pillager CaravansAug 5, 2026
• ARKANE DOMAINSAug 5, 2026
• Dungeon Now LoadingAug 5, 2026

Each entry links to its download page. Those pages are in Japanese, but the download button gives you the pack as a .zip resource pack you can open and read. Browse the full list.

[email protected]

Operated by Keel.