Guide
How to add bilingual subtitles to a video
Updated 2026-11-11
Bilingual subtitles put two languages in the same picture. One line is the source, the other is the translation. The viewer reads both, and the video you filmed stays the video you publish.
When two lines are clearer than one
Use bilingual subtitles when the audience is mixed. A classroom may want the original sentence and the translation. A family chat may include people who read one language and people who read the other. A product video may need the brand’s own wording visible next to the translation.
A single target line is calmer when everyone in the audience reads that language. Bilingual is the setting for the in-between case. You choose it before you render, and the preview shows both lines in the frame so you can see whether they fit.
Keep the picture readable
Two lines need a little room. A talking-head video with a plain wall behind the speaker gives the words a quiet place to sit. A busy street still works, and you should watch the preview on a phone, because that is where a tall video is usually seen.
Upload a file you have the right to use: MP4, MOV, MKV, AVI, FLV, or WebM, up to 2 GB, within 10 minutes. VidDub reads the speech from 17 source languages and writes one of 18 targets. The bilingual pair is the source you spoke and the target you picked.
How the two lines stay together
VidDub builds both lines from the same spoken sentence, then places them in the picture at that moment in the video. You are reading a pair, so a name on the top line and a different name on the bottom line is the thing to catch in the preview. Pause there. If the sentence is long, bilingual makes it longer, and the preview on a phone tells you whether the pair still fits.
You can prefer a single line for a fast cut and bilingual for a lesson. They are two renders of the same idea, and each one is its own upload. Keep the file names plain, such as the lesson title plus the word bilingual, so a teammate grabs the cut you meant.
Turn bilingual on, then preview
Sign in, upload, and pick the target language. Choose bilingual subtitles so both languages are burned into the picture. VidDub syncs the lines to the speech. You also receive a subtitle file with the finished video.
A catalog voice is separate from the subtitle choice. You can keep the original audio and let the two lines do the work, or add a catalog voice timed to the speech. Basic dubbing is free on the full video. The picture stays as you recorded it.
A short checklist before you download
- Both lines refer to the same sentence.
- Names match on both lines.
- Numbers and prices match.
- The lower line is still inside the frame on a phone.
- The first second is readable, because feeds crop tall videos.
- You know which language you want spoken, if you add a voice.
- The video is one you have the right to publish.
- You have a place to save the file the same day.
Save the bilingual video
The free preview after sign-in is the moment to decide that both lines belong. The full download uses minutes. Packs start at $3.90 for 30 minutes. Finished files stay for about 24 hours.
Publish the file as a normal video. The words are already in the picture, so a platform that shows its own captions is extra, and your bilingual line is still there. If you later want a single-language version, run that choice as its own upload and keep the two files apart.
A worked example: a three-minute class filmed in Chinese for students who also read English. You choose English and bilingual subtitles. Both lines appear in the preview, under the teacher. You fix nothing on the names, download the full video with minutes, and drop that file into the lesson page. Students who pause the video still see the sentence in both languages. The subtitle file is there too, if you want to paste one line into the lesson notes.
Related translations
Questions
Are the subtitles burned in?
Yes. They are in the picture, and you also get a subtitle file.
Can I use one language instead?
Yes. Single-language and bilingual are both available.
Does the voice replace the subtitles?
The voice is optional. The subtitles stay in the picture either way.
What should I watch the preview on?
A phone, if that is where the video will play.
Where do I start?
Sign in at viddubapp.com. The dubbing page covers the catalog voice.