Genera sottotitoli e traducili in locale.
Trasforma qualsiasi video o audio in sottotitoli SRT, VTT o ASS sincronizzati, con editor a livello di parola e una seconda lingua, tutto nel browser.
Sottotitoli di qualità broadcast. Zero upload.
Trascrizione Whisper, traduzione Marian e un vero editor di sottotitoli, tutto in locale.
100% privato
Il materiale non lascia mai il dispositivo. Decodifica, trascrizione e traduzione restano locali.
Accelerato con WebGPU
La trascrizione gira sulla GPU quando disponibile, con fallback WebAssembly.
Tempi per parola
I modelli Whisper con timestamp forniscono tempi per parola per sottotitoli serrati e karaoke.
Output bilingue
Traduci in una seconda lingua ed esporta le due tracce impilate nell'ordine che preferisci.
Dal materiale ai sottotitoli.
- 01
Trascina un video o audio
Trascina MP4, WebM, MP3, WAV o M4A: viene decodificato in locale, nulla viene caricato.
- 02
Whisper scrive i sottotitoli
Il parlato è trascritto in finestre sovrapposte, poi normalizzato secondo le regole broadcast.
- 03
Modifica, traduci, esporta
Correggi i sottotitoli nello studio, aggiungi una traduzione, poi scarica SRT, VTT, ASS, TXT o JSON.
About the subtitle generator
A free video-to-subtitle tool that listens to your audio with Whisper, writes timed cues, and can translate them into a second language — all inside the browser. It is built for creators, teachers, journalists and anyone captioning interviews, lectures, screen recordings or vlogs without handing raw footage to a cloud service.
How it works
The audio track is decoded with the Web Audio API and resampled to 16 kHz mono, then transcribed by a Whisper model running through Transformers.js. The file is walked in overlapping 30-second windows, so long recordings stream progress as they go and word-level timestamps stay accurate across window boundaries. Because the tool uses the timestamped Whisper builds, every cue also carries per-word timings, which drive the karaoke preview and the ASS karaoke export.
For translation, compact Marian (OPUS-MT) models are used, pivoting through English when the source and target have no direct model. Both the transcription and the translation models download once and are then cached, so a second run of the same language pair works offline.
Editing and quality
Generated cues are not set in stone. The studio pairs a live preview — with a broadcast-style subtitle overlay and a waveform timeline you can scrub — with a cue editor that supports inline text edits, splitting at the playhead, merging, duplicating, search & replace across both tracks, global time shifting, and full undo/redo. A quality panel flags every cue whose duration, reading speed, line length or overlap breaks normal subtitle conventions, and one click re-normalises the whole document.
Finished subtitles export as SRT, WebVTT, ASS, plain text or structured JSON, in the original language, the translation, or both stacked in either reading order.
Limits & requirements
The first run downloads model weights, which is the slowest step; afterwards they are cached. WebGPU (Chrome or Edge) makes transcription several times faster, and Safari or Firefox fall back to WebAssembly. Translation uses compact open models that are strong for general conversation and narration but should not be trusted for legal, medical or otherwise high-stakes wording. Very long recordings can exhaust memory on low-RAM devices; splitting the file is the workaround.
Privacy
Cloud captioning services receive your unedited footage and your scripts. Here nothing is uploaded: the video is decoded, transcribed and translated on your own machine, and the only files that leave the tab are the subtitles you choose to download.