echarts-headless-render

A lightweight CLI tool to render ECharts charts to PNG or Base64 using Puppeteer

Features

• 🖼️ Render ECharts options to PNG images
• 📄 Output Base64-encoded images for embedding
• ⚙️ Support custom width, height, and renderer (canvas or svg)
• 🚫 No HTTP server required—pure CLI invocation

Installation

npm install -g echarts-headless-render

Usage

ec-cli [options]

Options

| Flag | Description | Default | | -------------- | ------------------------------------------------------ | ------------ | | -i, --input | Path to JSON file or JSON string of the ECharts option | (required) | | -o, --output | Output file path (PNG) | output.png | | --width | Chart viewport width in pixels | 800 | | --height | Chart viewport height in pixels | 600 | | --base64 | Output Base64 string to stdout instead of file | false | | --renderer | Rendering mode: canvas or svg | canvas | | -h, --help | Show help | |

Examples

1. Render from JSON file

   ec-cli -i option.json -o sales-chart.png --width 1024 --height 768

2. Render and output Base64

   ec-cli -i option.json --base64 > chart.base64.txt

3. Render and output Svg

   ec-cli -i option.json --renderer svg -o chart.svg

4. Inline JSON string

   ec-cli -i '{"title":{"text":"Demo"},"xAxis":{"data":["A","B"]},"yAxis":{},"series":[{"type":"bar","data":[10,20]}]}' -o demo.png