Translation guide
The English phrase 'real time' refers to something happening immediately, without delay, or simultaneously with actual events. In Japanese, the most common equivalent is リアルタイム (riarutaimu), a loanword used widely in tech and daily life. Other expressions exist for specific contexts like live broadcasting or instantaneous processing.
Describing something that happens instantly, as events occur, with no perceptible lag.
The most common and versatile equivalent. Used in technology, gaming, news, and casual conversation.
このアプリはリアルタイムで情報を更新します。
This app updates information in real time.
リアルタイムの翻訳機能が便利です。
The real-time translation feature is convenient.
Means 'immediate' or 'instantaneous'. Often used in formal or technical contexts, such as finance or system responses.
即時の対応が必要です。
An immediate response is necessary.
システムは即時にデータを処理します。
The system processes data in real time.
Means 'simultaneous'. Can be used when emphasizing that two events occur at exactly the same time, but less common for 'real time' in tech contexts.
映像と音声が同時に再生されます。
The video and audio are played back in real time (simultaneously).
Referring to live television, radio, or internet streaming where content is transmitted as it happens.
Specifically means 'live broadcast'. Used for TV, radio, or streaming that is not pre-recorded.
その番組は生放送です。
That program is live (in real time).
生放送で試合を見ました。
I watched the match live.
Loanword from English 'live'. Commonly used for live music performances, but also for streaming or events.
Combines 'real time' with 'delivery/broadcast'. Used in online contexts, but 生放送 or ライブ are more natural.
リアルタイム配信の技術が進歩している。
Real-time streaming technology is advancing.
Describing systems that process data immediately as it is received, without buffering or delay.
The standard term in IT and engineering. Used for real-time operating systems, data processing, etc.
リアルタイムOSは組み込みシステムで使われます。
Real-time OSes are used in embedded systems.
リアルタイムデータ分析が重要です。
Real-time data analysis is important.
Means 'immediate processing'. Often used in technical documentation.
このシステムは即時処理に対応しています。
This system supports real-time processing.
リアルタイム is a general term for 'real time' in any context (tech, daily life). 生放送 specifically means 'live broadcast' and is used for TV/radio/streaming. Don't use 生放送 for real-time data processing.
リアルタイムで株価が変動する。
Stock prices fluctuate in real time.
そのニュースは生放送で伝えられた。
The news was reported live.
Do not translate 'real time' as 本当の時間 (hontō no jikan) or 実際の時間 (jissai no jikan). These mean 'actual time' in a philosophical sense, not the concept of immediacy.
リアルタイムのフィードバックが必要です。
We need real-time feedback.
そのゲームはリアルタイムのマルチプレイに対応しています。
The game supports real-time multiplayer.
I'm watching a live stream.
ライブでコンサートを楽しんだ。
I enjoyed the concert live.