Cast/edit/or

A browser-based editor for asciinema recordings (.cast files). 100% client-side — no server, no uploads, your files never leave the browser.

Give a try to the live app here: https://the8tre.github.io/casteditor/

Features

• Trim — keep only a time range
• Cut — remove a time range
• Speed — change playback speed globally or within a selection
• Remove Idle — cap long pauses to a maximum gap
• Add Idle — insert a pause of chosen duration at the playhead position
• Normalize Input — even out keystroke timing (recorded with --stdin option)
• Resize — change terminal dimensions
• Replace Text — find and replace text in output events
• Undo / Redo — full history (Ctrl+Z / Ctrl+Y)
• Export — download as asciicast v2 or animated SVG (with window chrome and cursor options)
• Load Sample — try the editor instantly with a built-in example recording
• Tool options (idle threshold, idle length, key interval) are remembered across sessions via localStorage

Create your own casts

• brew install asciinema
• Follow the directions here: https://docs.asciinema.org/getting-started/
• Format must be asciicast-v2
• Be sure to use the --stdin option if you want the user input to be captured and be able to use the Normalize Input feature
• Example: asciinema record --output-format asciicast-v2 --overwrite --stdin my_nice.cast

Getting Started

npm install
npm run dev

Open http://localhost:5173, then drag and drop a .cast file onto the page.

Build

npm run build   # outputs to dist/

Stack

• React 19
• MUI v5
• Vite 5
• asciinema-player v3
• svg-term (forked, browser-compatible build)
• TypeScript