Japanese is written with three scripts mixed together. For UI copy, picking the right script for each word is an aesthetic and trust decision — not a translation decision. AI tools default to a frequency-based choice that is often wrong for app context.
This article gives you a working framework and the common mistakes to avoid. For broader context, see the complete guide to Japanese app localization.
The Three Scripts in 30 Seconds
- Hiragana (ひらがな): phonetic, curvy, native Japanese words and grammar particles. Soft, warm, slightly informal.
- Katakana (カタカナ): phonetic, angular, foreign loanwords and brand names. Modern, slightly clinical.
- Kanji (漢字): ideographic, dense, Chinese-derived vocabulary. Formal, fast to scan, conveys precision.
Most Japanese sentences contain all three. The choice you control is which script for which word, given that several words have multiple legitimate spellings.
The Default Choices for Common UI Words
This is a reference list of words that have script-choice flexibility, with the choice that lands as natural in shipped apps.
| English concept | Wrong choice | Right choice | Why |
|---|---|---|---|
| Settings | セッティング | 設定 | Loanword exists but feels amateurish |
| Update | アップデート | 更新 / アップデート | Both work; 更新 in productivity, アップデート for app updates specifically |
| Share | シェア | 共有 | シェア is conversational; UI uses 共有 |
| Delete | デリート | 削除 | Loanword exists but isn't used |
| Photo | フォト | 写真 | Native word wins |
| Folder | フォルダー | フォルダー | Loanword wins |
| Calendar | カレンダー | カレンダー | Loanword wins |
| Notification | ノーティフィケーション | 通知 | Native wins |
| Account | アカウント | アカウント | Loanword wins |
| Profile | プロフィール | プロフィール | Loanword wins |
| Camera | カメラ | カメラ | Loanword wins |
| Settings → Profile | 設定 → プロフィール | 設定 → プロフィール | Mixed paths are normal |
| Edit | エディット | 編集 | Native wins |
| Cancel | 中止 | キャンセル | 中止 means "abort/halt"; UI uses katakana |
| Friend | フレンド | 友だち / 友達 | Native wins; 友だち more common in casual |
| Home | ホーム | ホーム | Loanword wins |
| Search | サーチ | 検索 | Native wins |
| Login | ログイン | ログイン | Loanword wins |
| Sign up | サインアップ | 登録 / 新規登録 | Native wins; サインアップ feels foreign |
| Sign in | サインイン | ログイン | Use ログイン instead |
| Tag | タグ | タグ | Loanword wins |
| Group | グループ | グループ | Loanword wins |
| Channel | チャンネル | チャンネル | Loanword wins (but 「チャネル」 in some contexts) |
The pattern isn't that one script always wins. It's that the conventions of shipped Japanese consumer apps dictate the choice, and those conventions are knowable.
When to Use Hiragana for a Word That Could Be Kanji
A word can be written in kanji or hiragana, and the choice affects feel.
子供 vs. こども vs. 子ども 出来る vs. できる 良い vs. いい 有難う vs. ありがとう
The kanji form is more formal, more print-like, slightly older. The hiragana form is softer, warmer, more conversational. The half-and-half (子ども) is a deliberate convention you'll see in education and parenting apps as a "soft, child-friendly" signal.
For consumer apps, the modern default is:
- 「できる」 (hiragana) — preferred over 「出来る」 in app copy.
- 「いい」 (hiragana) — preferred over 「良い」 in casual contexts.
- 「ありがとう」 (hiragana) — universal in apps. 「有難う」 is letter-writing register.
- 「ください」 (hiragana) — preferred over 「下さい」 in app copy. (「下さい」 is correct only when 「下」 means literal "below.")
These small choices add up. An app that defaults to kanji-heavy versions of these words feels noticeably more bureaucratic than one that uses the hiragana versions.
When Katakana Is the Right Call (and When It's Not)
Katakana in app UI lands in three contexts:
- Loanwords with no natural native equivalent. カメラ, アプリ, スマホ, ログイン.
- Technical terms where the loanword is canonical. ファイル, データ, ユーザー, タップ.
- Brand names and product features. "メルカリ" (the brand itself, written natively).
Where katakana goes wrong:
- Replacing native words for "modern" feel. 「スタート」 instead of 「開始」 in a finance app — looks try-hard.
- Replacing native concepts that aren't loanwords. 「メイン」 instead of 「主」 — sometimes works in casual apps, jarring in formal ones.
- Anglicizing every concept. "セッティングをセーブ" should be "設定を保存."
A useful instinct: if there's a kanji compound that an educated Japanese person would use in writing, prefer it. Reach for katakana when the loanword is what people actually say.
When to Use Kanji for a Word That Could Be Hiragana
The reverse problem. Some words, written in hiragana, look childish in adult app contexts.
「ありがとうございます」 — fine, casual-warm. 「ありがとうございました」 — formal, past-action thanks. 「ました」 in kanji 「致しました」 is keigo territory.
「お願いします」 — universal. 「おねがいします」 — only in children's apps or extremely casual ones.
「確認」 → ❌「かくにん」 — looks elementary-school. 「設定」 → ❌「せってい」 — same. 「削除」 → ❌「さくじょ」 — same.
For nouns that are kanji compounds in standard Japanese, write them in kanji. Writing them in hiragana reads as "this app is dumbing down for me," which is patronizing.
Mixed Scripts in a Single Phrase
Most Japanese phrases use multiple scripts. The conventions:
- 「アカウントを削除する」 — katakana noun + hiragana particle + kanji verb root + hiragana ending. Normal.
- 「ファイルが見つかりません」 — same pattern. Normal.
- 「お問い合わせはこちら」 — kanji-hiragana-kanji-hiragana-katakana? No, all kanji + hiragana. Normal.
The unspoken rule: don't try to push one script past where it stops being natural. Each word picks its own script; the sentence has whatever distribution falls out.
A Special Case: Furigana
Furigana are the small phonetic readings that appear above kanji in some Japanese text. In apps, furigana use is rare and intentional:
- Children's apps include furigana for any kanji not yet taught at the user's grade level.
- Apps for elderly users sometimes include furigana for less-common kanji.
- Reading-practice apps include furigana as a feature.
For mainstream consumer apps, do not include furigana. They make the UI feel like a textbook.
The Hardest Cases: When Both Scripts Look Right
Some words genuinely have parallel usage and the choice is brand-voice:
| English | Option A | Option B | Used by |
|---|---|---|---|
| Friend | 友だち | 友達 | LINE uses 友だち; many use 友達 |
| Reading | 読書 | 読書 | One option here, but 読み物 vs. 読書 is a brand choice |
| Recommendation | おすすめ | お勧め / オススメ | Casual apps use おすすめ; formal use お勧め |
| New | 新着 | NEW | Mixed badges often use Latin "NEW" |
For these, the right answer is: pick what your nearest competitor or aspirational reference app uses. Consistency with category convention beats individual decision-making.
A Workflow for Script Decisions
When localizing a string list, work through script choices in this order:
- Start with the native writer's instinct. Most words have an obvious right answer.
- For ambiguous words, check 3 reference apps in your category. What do top-shelf shipped apps use?
- For brand-voice words, document the choice. Add to your tone document so future translations stay consistent.
- Build a glossary. Each entry: English term → Japanese term in the chosen script → notes on why.
This glossary becomes the single source of truth for any future translator. Without it, every new translator re-decides the same questions and the app drifts.
Where to Go Next
- Japanese UX Writing: Microcopy That Feels Native
- Japanese Typography and Font Rendering for Mobile Apps
- Mobile UI Conventions Japanese Users Expect
- How to Make App Copy Sound Native in Japanese
We help teams build the kind of glossary described above — the document that keeps script choices consistent across every release. Contact us if you want one for your app.