Generate Vietnamese subtitles for your Thai videos

Where Thai words begin and end

Thai is written without spaces between words, so deciding where one word stops is part of recognition rather than something applied to the transcript afterwards. That matters more here than it would for a same-language transcript: the translation into Vietnamese runs on those segments, and a boundary in the wrong place changes what gets translated.

It is also why subtitle timings on Thai audio are worth spot-checking at the start and end of each line, where segmentation decisions land.

How Thai audio becomes Vietnamese subtitles

Audio in Thai (ไทย) is transcribed first, then translated into Vietnamese (Tiếng Việt). Because the translation runs on the transcript rather than on the audio, the Vietnamese subtitle file keeps the timings of the original Thai speech — each line appears at the moment it was actually said.

From the Thai script to Latin with tone diacritics

Thai is written in the Thai script and Vietnamese in Latin with tone diacritics, so the exported file uses a different writing system from the audio that produced it. The subtitle formats handle that — SRT and VTT are plain text and carry any script — but the font in whatever plays the file has to cover it.

This is the most common reason a Vietnamese subtitle track looks correct in an editor and shows boxes or blanks on a device. Test on the target platform before you publish a batch.

Vietnamese diacritics are part of the word

Vietnamese uses marks above and below its letters that change which word it is rather than only how it sounds. Stripping them, as some older subtitle tooling and a few upload pipelines still do, produces text that is wrong rather than merely plain.

Open the exported file once and confirm the marks survived before you rely on a workflow. If they did not, the problem is almost always an encoding setting rather than the Vietnamese text itself.

Why translate Thai video into Vietnamese

Thai is spoken principally in Thailand; Vietnamese in Vietnam. A Vietnamese subtitle track is what lets one recording reach both audiences without re-recording, re-editing or dubbing it.

Because subtitles are a separate file rather than part of the picture, you can attach several language tracks to the same video and let viewers pick.

About the Thai audio

Thai is written without spaces between words and is tonal, so segmentation happens during recognition rather than afterwards. The script has no capital letters and no full stops, which makes sentence boundaries in the transcript a judgement call worth reviewing.

About the Vietnamese subtitles

Vietnamese uses the Latin alphabet with a dense set of tone and vowel diacritics, and those marks are not decorative — dropping them changes the word. The transcript keeps them, so check that whatever you load the subtitle file into handles the full character set.

What a Thai to Vietnamese subtitle file looks like

Four lines of Thai speech, transcribed and translated, as they come out of the exported SRT. The timings are the Thai speaker's — translation does not move them, which is why the file drops onto the original video unchanged.

1
00:00:01,000 --> 00:00:03,240
Chào buổi sáng mọi người.

2
00:00:03,600 --> 00:00:06,120
Tôi sẽ chia sẻ chi tiết trong giây lát.

3
00:00:06,480 --> 00:00:09,300
Hãy viết câu hỏi của bạn bên dưới.

4
00:00:09,700 --> 00:00:12,040
Hẹn gặp lại lần sau.

What to check before publishing

• Names and places, which translation handles less reliably than ordinary prose.
• Idiom — a phrase that is natural in Thai may need loosening to read well in Vietnamese.
• That Latin with tone diacritics renders in your player, not just in the editor you exported from.
• That Vietnamese diacritics survived the export — they change the word, not just its pronunciation.
• Timing on fast exchanges, where two speakers overlap.