A lecture in Korean, a press conference in Arabic, a livestream in Portuguese, and nothing on screen you can read. Here's how to follow it as it plays.
It's one of the most common things people ask an AI assistant: "How do I translate this video? It doesn't have subtitles." Maybe it's a university lecture, a conference keynote, a government press briefing, or a creator's livestream. Downloading the file and running it through a translator afterwards works, eventually. To follow a video as it plays, you need something that turns its audio into translated text in real time. There are three good ways to do that, depending on where the video lives.
Many YouTube videos have captions even when they aren't showing: either uploaded by the creator or auto-generated by YouTube. If there are captions in any language, YouTube can machine-translate them into yours.
Click the CC button on the player. If it's greyed out or missing, the video has no captions, so skip to method 2 or 3.
Click the gear icon → Subtitles/CC. You'll see the available caption tracks.
Select Auto-translate, then your language. The translated captions follow the original track, including on replays of many livestreams.
The limits: it only works on YouTube, it only works when a caption track exists, and a translation built on auto-generated captions inherits their mistakes. Menu names also differ slightly on the mobile app.
Google Chrome has a built-in Live Caption feature that captions audio and video playing in the browser, on any site. Turn it on in Chrome settings → Accessibility → Live Caption, and a caption box appears whenever media plays. In recent versions Chrome can also translate those captions into other languages. Check the Live Caption settings to see which languages your version supports.
It's free and works well for a video on a website that isn't YouTube: a news clip, a course platform, a social media video. It shows one language at a time, it only covers audio inside Chrome, and it has no way to learn specialist vocabulary. Your operating system may also have its own captions; see how to turn on live captions on Mac and Windows.
Not every video lives in a browser. A lecture recording downloaded from a course portal, a clip sent over a messaging app, or a meeting recording on your drive plays in a desktop player like VLC, QuickTime, or the Windows Media Player, and browser tools can't hear it.
You have two routes. The slow one: run the file through a transcription service afterwards, then translate the transcript. That works for archiving, but you lose the ability to follow along as it plays. The fast one: use something that reads your system audio, so it captions whatever your computer plays, from any app. Your operating system's built-in captions do this in a limited set of languages; a desktop captioning app does it with translation.
One practical tip for either route: close other audio sources first. Notification sounds, a second tab playing music, or a call running in the background all end up in the captions when you capture system audio.
Unicaption listens to your browser tab or system audio, so it doesn't matter where the video comes from: YouTube, a course site, a Zoom recording, a livestream, or a file playing in a desktop player. It shows live captions in the original language with the translation beside them.
Captioning a live stream you're hosting rather than watching is a different job. See live captions for YouTube and Twitch streams.
| Your video | Best method | Why |
|---|---|---|
| YouTube video with a CC button | YouTube Auto-translate | Free, built in, nothing to set up |
| Video on another website, common language | Chrome Live Caption | Free and works on any site in Chrome |
| Lecture, webinar, or livestream in any of 60+ languages | Unicaption | Any source, original and translation side by side |
| Technical or specialist content | Unicaption | Custom dictionary for names and terms |
| Video file in a desktop player | Unicaption desktop app | Reads system audio, not just the browser |
More ideas for cleaner captions are in our guide to improving live caption accuracy.
If the YouTube video has any caption track, including auto-generated captions, click the gear icon → Subtitles/CC → Auto-translate and choose your language. If there is no CC option, use a tool that reads the audio directly. Unicaption captures tab or system audio and shows live captions with translation in 60+ languages, with 30 free minutes every week.
Yes. YouTube's Auto-translate is free when captions exist, and Chrome's Live Caption can caption and, in recent versions, translate media playing in the browser. Unicaption also has 30 free minutes every week, works on any video or livestream through tab or system audio, and shows the original and translation side by side in 60+ languages.
Use a live captioning tool that translates as the lecturer speaks. Unicaption works in the browser or as a macOS or Windows app, captions the lecture from your microphone in the room or from system audio online, and shows the translation side by side in 60+ languages. Add the course's key terms to its custom dictionary before class.
Yes. YouTube can auto-translate a live stream's captions if the stream has them. For any live stream on any site, Unicaption reads your tab or system audio and shows real-time captions with translation in 60+ languages. Audio is never stored and transcripts are deleted when the session ends.
30 free minutes every week. Any site, any player. Nothing stored.
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