How to get English subtitles on Japanese videos that have no captions (free)
Published: 2026-09-15
You found a Japanese video you want to watch: a talk, a game playthrough, a vlog, a commentary video. But there are no English subtitles, and when you open the caption menu there is nothing to translate from.
This guide shows how to get English subtitles on a recorded Japanese video playing in your browser, even when it has no captions at all. It is free and you do not need to install anything.
Why the video's own captions do not matter
Automatic caption translation on video sites works by translating captions that are already attached to the video. If a video has no captions, there is nothing to translate.
LiveSub works differently. It listens to the audio playing in the tab and makes subtitles from that. So it does not matter whether the video has captions, or which site it is on.
Everything runs on your own computer. The Japanese speech is recognised by a model running inside your browser, and the translation uses Chrome's built-in on-device translator. Your audio is not uploaded anywhere.
What you need
- Chrome or Microsoft Edge on a computer. Safari and Firefox do not work
- Not a phone or tablet. Mobile browsers cannot share tab audio
- A one-time download of the speech recognition model. For Japanese, the Balanced setting is about 590MB. After the first time, it is loaded from your browser's storage
No account, no extension, no payment, and no time limit.
Good videos to try
- YouTube videos without captions
- Recorded talks, lectures and presentations
- Game playthroughs, especially ones with a lot of commentary
- Vlogs and travel videos
- Commentary and reaction videos
Clear speech from one person at a time gives the best results. Loud background music makes it harder.
Step by step
1. Open LiveSub and set the direction
Open https://livesubweb.com/?lang=en in Chrome. Under "Translate from / to", choose Japanese → English.
This step matters. Japanese uses a different recognition model, so if you leave it on English → Japanese you will get garbled text instead of subtitles.
2. Choose a recognition setting
Under "Recognition setting", Balanced is the recommended starting point for Japanese. It handles place names and people's names well.
If your computer has a powerful GPU, try Japanese-tuned. It is a model retrained on Japanese only and is noticeably more accurate, even with fast, casual speech. It is much heavier, though, and the first download is about 730MB. It only appears when your browser can use the GPU.
If you are not sure, leave it on Balanced. You can change it later, even while subtitles are running.
3. Press "Try a sample" first
Before you use a real video, press "Try a sample". It plays a short built-in Japanese sample and shows subtitles without sharing any tab. It is a quick way to check that everything works on your computer. The first time, it waits for the recognition model to load.
4. Share the video's tab
Open the Japanese video in another tab. Back in LiveSub, press "Start (share a tab)". Chrome's sharing dialog appears:
- Pick the "Chrome Tab" section at the top
- Choose the tab playing the video
- Tick "Also share tab audio" at the bottom left
- Press Share
If you forget the audio checkbox, no sound reaches LiveSub and no subtitles appear.
5. Play the video
You can press play straight away. On the first run, the model keeps downloading in the background, and subtitles start as soon as recognition is ready. After that, they appear about one to two seconds after the words are spoken.
If no sound arrives for about 12 seconds, LiveSub tells you. Check that the video is playing and not muted. If you shared the wrong tab, press "Share again".
Tips for recorded videos
Pausing and rewinding work. The subtitles come from whatever audio is playing right now. If you pause, the subtitles pause too. If you rewind and play a part again, that part is subtitled again, so you can replay a line you missed.
Download the transcript. "Download transcript" saves the Japanese and the English with timestamps as a text file. It is useful for going back to a part later or taking notes.
Use the word list for names. Recognition often gets names wrong: people, places, game titles, in-game terms. Add the correct spellings to the "Word list", one per line (Japanese entries need at least 3 characters), and they are corrected automatically.
Watch in fullscreen. Press "Show in a floating window". The subtitles move into a small window that stays on top, so you can put the video in fullscreen and still read them.
Pick a display mode. Choose "Original and translation", "Translation only" or "Original only". If you are learning Japanese, seeing both is helpful.
Honest limits
- It is machine translation. You get the gist, but nuance, jokes and wordplay are often lost
- The Japanese text can be wrong too. Speech recognition mishears words, especially names
- About one to two seconds of delay behind the audio
- Music, sound effects and overlapping voices reduce accuracy
- Only the audio is translated. Text shown on screen is not
- Computer only. It needs Chrome or Edge on a desktop or laptop
Related guides
- For live broadcasts, see how to translate a Japanese livestream in real time
- For VTuber streams, including tips for names, see watching Japanese VTuber streams with English subtitles
Try it
Open the Japanese video you want to watch, then open LiveSub on your computer: