A local timeline: two picture tracks, titles, transitions, and two audio tracks. The preview stays in the tab. Export writes an MP4 or WebM with the same ffmpeg build as the other video tools.
How to use it
Import video, stills, or audio from this device. Drag a thumbnail onto a track, or click it to place it at the end of that track. The playhead splits a clip, and the trim buttons cut the head or tail at the playhead.
Titles take a font size, a colour, a position, and a fade. Transitions (crossfade, fade to black, slide, wipe) apply to the selected incoming clip. Subtitles can be an SRT or VTT, or Whisper tiny can write cues from a clip you already imported.
Sessions save the timeline and the files in this browser. Export is H.264 and AAC in an MP4 at 720p or 1080p, or WebM. The aspect you pick (16:9, 9:16, 1:1, 4:5) is letterboxed on the background colour. Nothing is uploaded.
Tips
- Space plays and pauses. S splits. Delete removes the selected clip. Arrow keys step one frame. Cmd or Ctrl+Z undoes.
- Put the talking shot on V1 and a still or a second angle on V2. A crossfade belongs on the clip that comes in.
- The first export downloads ffmpeg, about 31 MB, then caches it. A long 1080p timeline takes a while because the encoder is single-threaded.
FAQ
Does the editor upload the timeline?
No. Files stay in the tab. A saved session is stored in IndexedDB on this device. Export runs in ffmpeg.wasm.
Which formats can I export?
MP4 uses H.264 and AAC at 720p or 1080p. WebM uses VP8 and Opus. The frame size follows the aspect you picked.
Can I generate subtitles here?
Yes. Import an SRT or VTT, or run Whisper tiny on a video or audio clip already in the bin. That is the same on-device model as the subtitle generator. The first run downloads the weights.
Will this work on a phone?
The page loads, and you can import and export. A wide screen is easier for the timeline. The page says so on a narrow window.
License
Encoding uses the single-thread ffmpeg.wasm build shipped with Cutshed. The JavaScript wrapper (@ffmpeg/ffmpeg and @ffmpeg/util) is MIT. The core binary is GPL-2.0-or-later because the build enables GPL components, including libx264, libmp3lame, libvorbis, and native AAC and FLAC. That license covers the encoder, not your recording. Titles use DejaVu Sans, shipped from this site (Bitstream Vera license; DejaVu changes are in the public domain). Whisper, when you generate subtitles, is MIT via Transformers.js (Apache-2.0).