How to say "prompt" in Japanese

• 即時そくじCommon
  no-adjective, adverbCovers 'prompt' as in immediate, done the moment it is needed — a prompt response or payment. It presents the action as happening in real time, with no delay at all.
  彼かれは即時そくじ断行だんこうを強調きょうちょうした。↗

  He put emphasis on the necessity for immediate action.
• 速やかすみやかCommon
  na-adjectiveMatches 'prompt' when asking for or describing action taken without delay, as in requests and instructions. The nuance is smooth, orderly swiftness rather than urgency.
  決定けっていの後あとすみやかに実行じっこうに移うつして欲ほしい。↗

  I want quick action subsequent to the decision.
• 早急そうきゅうJLPT N1approx.Common
  na-adjective, no-adjective'Prompt' with a strong sense of urgency — something must be handled immediately, as soon as possible. Typical of business messages pressing for immediate action on a matter.
  １月がつ２０日にち（月曜日げつようび）の午前中ごぜんちゅうに最終さいしゅうの議事ぎじ事項じこうを出だしますので、早急さっきゅうにお返事へんじを下ください。↗

  We'll release the final agenda on the morning of Monday, January 20, so please reply quickly.
• 早いはやいJLPT N5approx.Common
  i-adjectiveThe plain adjective for speed; use it when 'prompt' really just means fast or quick. It describes how fast something is, without stressing that it happened without delay.
  子供こどもは成長せいちょうが早はやい。↗

  Children grow very quickly.
• 機敏きびんCommon
  na-adjective, nounCovers 'prompt' in the sense of quick and alert: reacting or moving swiftly and sharply. It suits descriptions of nimble action and quick judgment.
  警察けいさつは力ちからがあって、動作どうさが機敏きびんでなければならない。↗

  A policeman should be strong and quick in action.

For 'prompt' meaning done without delay, choose 即時 or 「速やか」, with 早急 adding urgency; 「早い」 is the plain word for fast, and 機敏 describes quick, alert reactions.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 即時そくじprompt
• 速やかすみやかquick
• 早急そうきゅうimmediate
• 早いはやいfast
• 機敏きびんquick
• 手っ取り早いてっとりばやいquick
• 促すうながすto urge
• 迅速じんそく(very) quick
• 至急しきゅうurgent
• プロンプトprompt
• 入力促進にゅうりょくそくしんprompt
• 入力要求にゅうりょくようきゅうprompt
• てきめんimmediate (effect, result, etc.)
• 素早いすばやいquick (understanding, judgement, etc.)
• 直截ちょくせつdecisive
• 敏捷びんしょうquick (thinking)