Video Editor
Edit videos locally with a timeline, text, effects, and MP4 export
Your input stays in this browser while it is processed.
What does this calculator do?
Edit short videos in one local browser workspace: combine clips, trim ranges, split, reorder, adjust playback and color, add titles, and export a validated MP4 file.
Inputs
- One or more video clips supported by the browser
- Optional trim, speed, volume, canvas, color, and text settings
Outputs
- A non-destructive local project saved in this browser
- A playable MP4 export at 144p through 2160p when the browser provides real H.264/AAC recording
Formula and method
The editor keeps source clips unchanged and stores only project instructions in IndexedDB. Frames are composited on a canvas and encoded with the browser MediaRecorder API; the output is signature- and playback-validated before download.
Worked example
Import two clips, trim the first to 8 seconds, move the second before it, add a title, and export a 720p MP4 without uploading either source.
How to interpret the result
This is a local-first editor for short projects and ordinary browser hardware. It exports MP4 only when the browser exposes a real MP4/H.264 encoder and validates the resulting container before download.
Common mistakes
- Closing the browser before a project is saved
- Selecting 1440p or 2160p on hardware without enough browser memory
- Using very large or long source files beyond available browser memory
Assumptions
- The browser can decode the imported video and expose canvas captureStream/MediaRecorder
- Audio processing follows browser media-element capabilities
- Source files remain available in this browser profile
Limitations
- MP4 export requires native browser H.264/AAC MediaRecorder support
- Complex transitions, GPU effects, and frame-accurate professional color workflows are outside the lightweight editor
- Private browsing modes may disable IndexedDB
Frequently asked questions
Are my videos uploaded?
No. Source files and project metadata stay in the browser; the editor does not send them to a server.
What format does export use?
A real MP4 video encoded by a compatible browser and validated before download; unsupported browsers show an error instead of a fake file.