What Subtightl does
Subtightl turns the speech in your video into captions that move with every word, in a look designed for your kind of content, and exports a video you can post anywhere.
Subtightl automatically transcribes the speech in a video with word-level timing, shows it as animated captions in one of six designed styles, lets you fix any word, and exports a new video with the captions burned into the picture. It works in 10 languages and can caption other languages in English.
Automatic, word-by-word captions
Pick a video and Subtightl transcribes the speech with state-of-the-art speech recognition, down to the timing of each word. That timing drives the animation: in five of the six styles the word being spoken is marked as it is said, and in Soft the words arrive one by one — either way the captions follow the voice instead of appearing in blocks.
Languages
Captions in English, Spanish, Portuguese, French, German, Italian, Japanese, Korean, Chinese and Russian. Japanese, Korean and Chinese are set in Noto typefaces made for those scripts — serif styles stay serif — so the styles still look designed rather than falling back to a system font.
English captions for any of them
Speaking another language but posting for an English-speaking audience? Choose English captions and Subtightl writes them from the original speech — or show both lines, original and English, at once. English captions cost an extra half of the clip's length on top of the transcription — a 60-second clip uses 60 + 30 seconds (see pricing).
Six designed caption styles
Instead of a list of fonts, Subtightl has six complete looks — Punch, Clean, Soft, Bounce, Lyric and Elegant — each with its own type treatment, way of revealing words, how — or whether — it marks the spoken word, and motion, made for a kind of creator. Each can be recoloured, resized and moved up or down. See them on real videos →
Fix any word
Speech recognition is very good, not perfect — names and slang trip it up. Tap a line to correct its words before exporting. Your project is saved, so you can come back, change the style and export again without transcribing twice.
Export with the captions burned in
The result is a new video with the captions drawn into the picture at your video's resolution — not a subtitle file that platforms may ignore or restyle. It plays the same on every app: Instagram, TikTok, YouTube, WhatsApp, anywhere. The finished video is saved to your gallery and kept in the app's My videos list.
No ads, no forced watermark
There are no ads in the app, and your exports carry no watermark unless you turn one on in Settings. You pay for captioning time and nothing else.
Privacy
Only the audio of your clip is sent for transcription; the video itself stays on your phone and is rendered there. You can have your account and its data deleted at any time — here is how. Details in the privacy policy.