Paste hiragana above and the katakana appears as you type. Nothing is uploaded and nothing is installed — the conversion runs in your browser.
The two scripts are the same list of sounds
Hiragana and katakana are two ways of writing the same 46 syllables. あ and ア are both a; か and カ are both ka. Japanese uses both at once because the choice of script carries meaning rather than sound:
- Hiragana writes native Japanese words and all the grammar — the endings, particles and connectives that hold a sentence together.
- Katakana writes loanwords, foreign names, onomatopoeia, and the occasional word an author wants to stand out. コンピューター is konpyūtā, from "computer".
Converting between them changes how a word looks, not how it sounds.
Why the conversion is exact
The two syllabaries sit in parallel Unicode blocks, a fixed distance apart: hiragana runs from U+3041 and katakana from U+30A1, exactly 0x60 higher. So every hiragana character has one katakana counterpart and the conversion is arithmetic rather than a lookup table with judgement calls in it.
Three details that follow from that, and that a careless converter gets wrong:
- Small kana and voiced marks are ordinary characters. っ → ッ, ゃゅょ → ャュョ, が → ガ, ぱ → パ. They are separate code points in the same run, so they convert like everything else.
- The iteration marks sit outside the run. ゝ and ゞ pair with ヽ and ヾ, and are handled separately.
- Four katakana have no hiragana form. ヷヸヹヺ exist only in katakana, so the reverse direction leaves them alone rather than producing an unassigned character.
The long vowel mark stays as it is
ー (U+30FC) is shared by both scripts, so it is carried across unchanged: らーめん becomes ラーメン. It is far more common in katakana, because that is where loanwords live and loanwords are full of long vowels, but it is not katakana-only.
That matters going the other way too. Converting ラーメン back gives らーめん — correct, and worth knowing if you expected らあめん.
Examples
| Hiragana | Katakana | What it shows |
|---|---|---|
| ひらがな | ヒラガナ | Basic syllables |
| がっこう | ガッコウ | Voiced mark and small tsu |
| きょう | キョウ | Small yo |
| らーめん | ラーメン | The long vowel mark carried across |
| 私はねこ | 私ハネコ | Kanji untouched, hiragana converted |
When you would use this
- Writing a loanword or a foreign name, which convention puts in katakana.
- Reading a menu or a sign written in katakana when you know the word in hiragana.
- Making study material — the same vocabulary list in both scripts.
- Normalising text before comparing it, where the script should not count as a difference.