Twinsub
Subtitles for online courses and lectures
A one-hour lecture takes a lot of time to listen to, take notes on and review. With timecoded subtitles you can search for a keyword and jump to that spot, and read along as you watch.
Two common situations
A foreign-language course or open class: you want bilingual text
Drop it into Twinsub for a bilingual SRT (for example an English course with a target language of your choice): the target on top and the original below. Load it in a player such as IINA or VLC to listen to the original audio while reading the translation, and look back at the original wherever you get stuck. For a long course, drop several files in and let them queue.
A lecture or recording in your own language: you want punctuated subtitles
When source and target are the same language, for example an English lecture with English as the target, only a single-language file is written (such as .en.srt) and nothing is translated. The recognized text is punctuated and broken by meaning, so you can use it directly as subtitles or as the base for a transcript.
Handy ways to work with it
- Use subtitles as a table of contents: an SRT is a text file, so search it for a keyword, find the timecode, then jump to it in the video.
- For specialist courses, list the terms first: replacing terms globally while proofreading is far quicker than fixing cue by cue; see checking and editing SRT.
- Run internal training videos locally with confidence: the video is not uploaded, which suits material that cannot leave your hands. The difference is explained in local vs cloud transcription.
About the free allowance and long videos
The free version processes only the first 10 minutes of each video; everything else is the same. Lectures are usually longer than that, so processing the full video needs the one-time purchase (no subscription). We suggest judging recognition and translation quality on the first 10 minutes before you decide whether to buy.
Limits to know about
- Heavy accents, several people talking over each other and a lot of room echo raise the error rate.
- It does not separate speakers for now, so in a multi-person discussion you cannot tell who said what.
- Subtitles are for reference; check them before quoting or publishing.
Updated 2026-10-11. Back to the Twinsub home page