editly

A tool and framework for declarative non‑linear video editing built on Node.js and ffmpeg. It lets users programmatically assemble videos from clips, images, audio, and titles, applying smooth transitions, music overlays, and automatic scaling or letterboxing to any target resolution or aspect ratio. The CLI can process a JSON5 edit spec, while the JavaScript API offers deeper flexibility, including custom HTML5 Canvas/Fabric.js screens, GL shaders, picture‑in‑picture, and B‑roll sub‑clips.

The software targets developers and content creators who want to generate videos through code rather than manual editing. Typical use cases include slideshows with text overlays, fast‑paced trailers, tutorials, news stories, animated GIFs, and podcasts with mixed audio tracks. It supports automatic audio cross‑fading, ducking, normalization, and can output to common formats such as MP4 or GIF.

Distinctive features include streaming‑based editing that reduces storage needs, a pluggable interface for dynamic content, and built‑in defaults that create colorful edits with random palettes and effects. The project is stable, CLI‑available, and runs on Windows, macOS, and Linux with ffmpeg in the system path.