Translation guide
How to express 'keep secret' in Japanese, from casual to formal, including warnings about literal translations.
秘密にしてください。
Please keep it a secret.
The general act of keeping information hidden from others.
The most common and neutral way to say 'keep something secret'. Literally 'make into a secret'.
このことは秘密にしてください。
Please keep this a secret.
He kept the plan secret.
Casual, everyday word for 'secret'. Often used among friends or family. Can be used as '内緒にする' (keep it a secret) or '内緒だよ' (it's a secret).
Literally 'to be silent'. Implies keeping quiet about something, often used when you choose not to reveal information.
このことは黙っていてください。
Please keep quiet about this.
彼は何も言わずに黙っていた。
He kept silent without saying anything.
Formal expression meaning 'not to disclose' or 'keep confidential'. Often used in business or official contexts.
この情報は口外しないでください。
Please do not disclose this information.
Literary/poetic word meaning 'to keep hidden (in one's heart)'. Used for emotions or thoughts.
彼女は心に秘めた思いを誰にも話さなかった。
She never told anyone the feelings she kept hidden in her heart.
Specifically about guarding someone else's confidential information.
Literally 'protect a secret'. Emphasizes the act of safeguarding the secret.
友達の秘密を守るのは大切だ。
It's important to keep a friend's secret.
Formal, somewhat stiff expression meaning 'not to tell others'. Often used in promises.
この話は他言しないと約束します。
I promise not to tell anyone about this.
Hiding information from a particular person or group.
Casual pattern: 'keep it a secret from ~'. Replace 〜 with the person.
母には内緒にしておいて。
Keep it a secret from Mom.
Neutral pattern: 'keep it a secret from ~'.
彼には秘密にしている。
I'm keeping it a secret from him.
Emphasizing the act of not speaking about something.
Literally 'shut one's mouth'. Stronger, more dramatic way to say 'keep silent'.
彼はその件については口を閉ざした。
He kept his mouth shut about the matter.
Idiom meaning 'to impose a gag order'. Used in formal or organizational contexts.
政府はその事件に箝口令を敷いた。
The government imposed a gag order on the incident.
The English phrase 'keep secret' cannot be directly translated word-for-word into Japanese. Expressions like '秘密を保つ' (keep a secret) are understandable but unnatural. Use the options above instead.
秘密 (himitsu) is the standard word for 'secret' and can be used in most situations. 内緒 (naisho) is more casual and intimate, often used among close friends or family. 内緒 implies a shared, often light-hearted secret, while 秘密 can be serious or formal.