Genereer ondertitels en vertaal ze lokaal.
Zet elke video of audio om in getimede SRT-, VTT- of ASS-ondertitels — met een editor op woordniveau en een tweede taal, volledig in je browser.
Ondertitels van broadcastkwaliteit. Nul uploads.
Whisper-transcriptie, Marian-vertaling en een echte ondertitel-editor, alles lokaal.
100% privé
Je materiaal verlaat het apparaat nooit. Decoderen, transcriberen en vertalen gebeurt lokaal.
WebGPU-versneld
Transcriptie draait op je GPU wanneer beschikbaar, met WebAssembly-terugval.
Timing per woord
Whisper-modellen met tijdstempels geven timing per woord, voor strakke ondertitels en karaoke-export.
Tweetalige uitvoer
Vertaal naar een tweede taal en exporteer beide sporen gestapeld in elke volgorde.
Van materiaal naar ondertitels.
- 01
Sleep een video of audio
Sleep MP4, WebM, MP3, WAV of M4A erin — lokaal gedecodeerd, niets wordt geüpload.
- 02
Whisper schrijft de ondertitels
Spraak wordt in overlappende vensters getranscribeerd en daarna genormaliseerd volgens broadcastregels.
- 03
Bewerk, vertaal, exporteer
Corrigeer ondertitels in de studio, voeg een vertaling toe en download SRT, VTT, ASS, TXT of 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.