Status: Captions.js is nearing its first public release. The library is under active development and a full-featured version is expected around July 2026.

If Captions.js is useful for you, a quick ⭐ on GitHub helps a lot.

Captions.js

Render styled animated captions on canvas — works both on client and server side using Node.js and FFmpeg.

Live Demo

Docs & API Reference

Features

• Client + Server Rendering: Use the same captions engine in the browser and in Node.js/FFmpeg pipelines.
• Highly Customizable Visuals: Control fonts, colors, stroke, shadows, positioning, and animation presets.
• Word-Level Timing Precision: Render and highlight captions frame-by-frame with smooth active-word transitions.
• Sentence-Aware Output: Keeps caption display coherent by respecting sentence structure.

Installation

To install Captions.js, use npm or yarn:

npm install captions.js

or

yarn add captions.js

For development see DEVELOPMENT.md.