文字化け

• 読み: もじばけ
• ローマ字: mojibake
• 漢字の分解: 文 (writing, text) + 字 (character, letter) + 化 (transform, change) + け (nominal suffix from 化ける, to transform) — literally 'characters that have transformed (into something unrecognisable)'
• 発音: /mo.dʑi.ba.ke/

意味

Garbled text caused by an encoding mismatch — when Japanese characters display as nonsensical symbols because the wrong character encoding was applied.

文字化け (mojibake) describes what happens when text encoded in one character set is read with a different one, producing a jumble of meaningless symbols. It is a phenomenon with deep roots in Japanese computing history: Japan's complex writing system required its own encoding standards (Shift-JIS, EUC-JP) that were incompatible with Western systems, making mojibake a widespread headache throughout the 1990s and 2000s. Although Unicode has largely solved the problem, mojibake still occurs with old files, certain email clients, and cross-platform data transfers. The term is used both as a technical noun and as a casual verb — 文字化けする (to become garbled).

例文

1. メールを開いたら全部文字化けしてて何も読めなかった。
2. 文字化けしてる古いテキストファイル、エンコーディング変えたら直った。
3. このサイト、たまに文字化けするんだよね。スマホだと特に。

使い方ガイド

場面: tech discussions, casual conversation, workplace, online help forums

トーン: frustrated, matter-of-fact

正しい言い方

• このCSVファイル文字化けしてるから、UTF-8で保存し直して。 (This CSV file has garbled text — please re-save it in UTF-8.)
• 昔のウェブサイト開くと文字化けしてることあるよね。 (Old websites sometimes display garbled text when you open them, don't they.)

避ける言い方

• 「文字化け」をただの誤字や誤変換と混同しない — 文字化けはエンコーディングの問題で、タイポとは別 (Don't confuse 文字化け with a simple typo or wrong kanji conversion — mojibake is specifically an encoding issue, not a typing mistake)

よくある間違い

• Learners sometimes write 文字バケ with katakana バケ — the correct form uses hiragana け throughout: 文字化け
• Thinking the problem is purely historical — mojibake still occurs regularly with legacy systems, CSV exports, and email in Japanese business environments

起源と歴史

文字化け comes from 文字 (character/letter) + 化け (transformation, as in becoming something else — e.g. お化け, ghost). The combination vividly describes characters 'transforming' into unrecognisable symbols. The phenomenon became acutely common in Japan due to competing character encoding standards (Shift-JIS vs EUC-JP vs ISO-2022-JP) that coexisted through the 1990s and 2000s before UTF-8 standardisation.

文化的背景

時代: 1980s–present; peak prevalence 1990s–2000s

世代: All ages; older users have strong nostalgic frustration with it

社会的背景: Universal among computer users

地域メモ: Uniquely significant in Japan due to the historical complexity of Japanese character encoding. The word mojibake itself has been adopted into English-language tech writing as the standard term for this phenomenon.