Package Exports

@resvg/resvg-js
@resvg/resvg-js/index.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@resvg/resvg-js) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

resvg-js

resvg-js is a high-performance SVG renderer and toolkit, powered by Rust based resvg and napi-rs.

Features

Fast, safe and zero dependencies.
Convert SVG to PNG, includes cropping, scaling and setting the background color.
Support system fonts and custom fonts in SVG text.
v2: Gets the width and height of the SVG and the generated PNG.
v2: Support for outputting simplified SVG strings, such as converting shapes(rect, circle, etc) to <path>.
v2: Support WebAssembly.
No need for node-gyp and postinstall, the .node file has been compiled for you.
Cross-platform support, including Apple M Chips.

Installation

Node.js

npm i @resvg/resvg-js

Browser(Wasm)

<script src="https://unpkg.com/@resvg/resvg-wasm"></script>

Example

This example will load Source Han Serif, and then render the SVG to PNG.

node example/index.js

Loaded 1 font faces in 0ms.
Font './example/SourceHanSerifCN-Light-subset.ttf':0 found in 0.006ms.
✨ Done in 55.65491008758545 ms

SVG	PNG
CC BY 3.0: Niabot	CC BY 3.0: Niabot

Usage

Node.js

const { promises } = require('fs')
const { join } = require('path')
const { Resvg } = require('@resvg/resvg-js')

async function main() {
  const svg = await promises.readFile(join(__dirname, './text.svg'))
  const opts = {
    background: 'rgba(238, 235, 230, .9)',
    fitTo: {
      mode: 'width',
      value: 1200,
    },
    font: {
      fontFiles: ['./example/SourceHanSerifCN-Light-subset.ttf'], // Load custom fonts.
      loadSystemFonts: false, // It will be faster to disable loading system fonts.
      defaultFontFamily: 'Source Han Serif CN Light',
    },
  }
  const resvg = new Resvg(svg, opts)
  const pngData = resvg.render()
  const pngBuffer = pngData.asPng()

  console.info('Original SVG Size:', `${resvg.width} x ${resvg.height}`)
  console.info('Output PNG Size  :', `${pngData.width} x ${pngData.height}`)

  await promises.writeFile(join(__dirname, './text-out.png'), pngBuffer)
}

main()

WebAssembly

Although we support the use of Wasm packages in Node.js, this is not recommended. The native addon performs better.

Browser

<script src="https://unpkg.com/@resvg/resvg-wasm"></script>
<script>
  ;(async function () {
    // The Wasm must be initialized first
    await resvg.initWasm(fetch('https://unpkg.com/@resvg/resvg-wasm/index_bg.wasm'))
    const opts = {
      fitTo: {
        mode: 'width', // If you need to change the size
        value: 800,
      },
    }

    const svg = '<svg> ... </svg>' // Input SVG, String or Uint8Array
    const resvgJS = new resvg.Resvg(svg, opts)
    const pngData = resvgJS.render(svg, opts) // Output PNG data, Uint8Array
    const pngBuffer = pngData.asPng()
    const svgURL = URL.createObjectURL(new Blob([pngData], { type: 'image/png' }))
    document.getElementById('output').src = svgURL
  })()
</script>

See playground, it is also possible to call Wasm in Node.js, but there is a performance penalty and this is not recommended.

Benchmark

Running "resize width" suite...
  resvg-js(Rust):
    12 ops/s, ±22.66%   | fastest 🚀

  sharp:
    9 ops/s, ±64.52%    | 25% slower

  skr-canvas(Rust):
    7 ops/s, ±3.72%    | 41.67% slower

  svg2img(canvg and node-canvas):
    6 ops/s, ±16.94%    | slowest, 50% slower

Support matrix

	node12	node14	node16
Windows x64	✓	✓	✓

Windows x32	✓	✓	✓

Windows arm64	✓	✓	✓

macOS x64	✓	✓	✓

macOS arm64(M1)	✓	✓	✓

Linux x64 gnu	✓	✓	✓

Linux x64 musl	✓	✓	✓

Linux arm gnu	✓	✓	✓

Linux arm64 gnu	✓	✓	✓

Linux arm64 musl	✓	✓	✓

Android arm64	✓	✓	✓

Android armv7	✓	✓	✓

Test or Contributing

Install latest Rust
Install Node.js@10+ which fully supported Node-API
Install wasm-pack
```
curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
```
Normally wasm-pack will install wasm-bindgen automatically, but if the installation fails due to network reasons, please try to install it manually.
```
cargo install wasm-bindgen-cli
```
On computers with Apple M chips, the following error message may appear:

Error: failed to download from https://github.com/WebAssembly/binaryen/releases/download/version_90/binaryen-version_90-x86_64-apple-darwin.tar.gz

Please install binaryen manually:
```
brew install binaryen
```

Build Node.js bindings

npm i
npm run build
npm test

Build WebAssembly bindings

npm i
npm run build:wasm
npm run test:wasm

Roadmap

I will consider implementing the following features, if you happen to be interested, please feel free to discuss with me or submit a PR.

Support async API
Upgrade to napi-rs v2
Support WebAssembly
Output usvg-simplified SVG string
Support for getting SVG Bounding box
Support for generating more lossless bitmap formats, e.g. avif, webp, JPEG XL

Release package

We use GitHub actions to automatically publish npm packages.

# 1.0.0 => 1.0.1
npm version patch

# or 1.0.0 => 1.1.0
npm version minor

License

MPLv2.0