Translation guide
How to express doing something without permission in Japanese, from casual to formal, including warnings about literal translations.
The speaker did something without obtaining prior consent, often implying it was wrong or presumptuous.
The most common and natural way to say 'without permission' or 'on one's own authority'. Often carries a negative nuance of doing as one pleases.
彼は私のパソコンを勝手に使った。
He used my computer without permission.
勝手に部屋に入らないでください。
Please don't enter the room without permission.
More formal than 勝手に. Often used in official contexts, rules, or written warnings. Literally 'without notice'.
無断で駐車すると罰金です。
Parking without permission will result in a fine.
資料を無断でコピーしてはいけません。
You must not copy the materials without permission.
Directly means 'without permission'. Formal and often used in legal or procedural contexts.
許可なく撮影することは禁止されています。
Photography without permission is prohibited.
Literally 'without notice/announcement'. Used when someone does something without informing the relevant person, often in formal or written contexts.
彼は断りなく会議を欠席した。
He was absent from the meeting without permission.
Taking or using another person's property without their consent.
The most natural way to say 'use without permission'. 勝手に adds the nuance of doing as one pleases.
私の自転車を勝手に使わないで。
Don't use my bicycle without permission.
A noun meaning 'unauthorized use'. Common in formal warnings or rules.
無断使用は固くお断りします。
Unauthorized use is strictly prohibited.
Going into a room, building, or area without authorization.
Natural for everyday situations, like entering someone's room.
勝手に入ってごめんなさい。
Sorry for coming in without permission.
Standard sign for 'No trespassing' or 'Keep out'.
この先は無断立ち入り禁止です。
Beyond this point, entry without permission is prohibited.
Duplicating content, documents, or media without authorization.
Specifically for reposting or reproducing online content without permission.
無断転載はご遠慮ください。
Please do not reproduce without permission.
Used for physical or digital duplication, often in copyright contexts.
このCDの無断複製は法律で禁じられています。
Unauthorized reproduction of this CD is prohibited by law.
Do not translate 'without permission' word-for-word as 許可なしで (kyoka nashi de) in casual speech; it sounds stiff. Use 勝手に for everyday situations.
勝手に見ちゃダメだよ。
Don't look without permission.
勝手に is casual and subjective, implying the speaker feels it was done selfishly. 無断で is objective and formal, focusing on the lack of authorization. Use 勝手に in conversation, 無断で in rules or official notices.