Length and layout
Japanese is far fewer characters than the English original. Both languages are written left to right, so the layout does not change — only the wording and line length do.
English → 日本語
Translate English video into Japanese subtitles
Upload a video in English. SubFlow transcribes the speech, translates every caption into Japanese, and keeps both languages on the same timeline so you can review them side by side — then export subtitles, a subtitled video, or a Japanese dub.
30 free minutes monthly · No credit card
What changes
English and Japanese, side by side.
| English (spoken) | Japanese (subtitles) | |
|---|---|---|
| Script | Latin | Japanese (kana and kanji) |
| Direction | Left to right | Left to right |
| Reading speed | 15–17 chars/sec | well below Latin scripts chars/sec |
| Line length | about 42 chars | about 13–16 chars |
| AI dub voice | en-US | ja-JP |
Getting Japanese right
Japanese is read more slowly per character than Latin text, so keep lines short — about 13–16 characters — and let long sentences run across two captions.
Workflow
From English to Japanese in three steps.
Upload the English video
Add a video or audio file. SubFlow transcribes the English speech into timed captions.
Translate into Japanese
Pick Japanese as the target. Every caption is translated with the surrounding lines as context, then shown beside the original.
Review and export
Fix names and terms, split any caption that runs long, then export Japanese or bilingual subtitles, a subtitled video, or a Japanese dub.
Common questions
English to Japanese, answered.
Can SubFlow recognise English speech automatically?
Yes. Leave the source on automatic detection or pick English yourself. Accents, fast speech and overlapping speakers are handled well by the Whisper model; background music is the most common cause of a dropped line.
Will the Japanese subtitles fit on screen?
Japanese reads comfortably at well below Latin scripts characters per second with about 13–16 characters per line. Japanese is far fewer characters than the English original. Review the longest captions and split any that crowd two lines.
Can I dub a English video into Japanese?
Yes, on the Pro plan. The Japanese dub uses a ja-JP voice and is spoken from the translated subtitles, so correcting a line in the editor changes what the voice says.
Can I export English and Japanese together?
Yes. Export the Japanese subtitles alone, the original English, or a bilingual SRT with both on each caption — or burn either into the video.