@insomnia-dev/convert-svg-to-png

A Node.js package for converting SVG to PNG using headless Chromium.

• Install
• CLI
• API
• Other Formats
• Bugs
• Contributors
• License

Install

Install using npm:

$ npm install --save convert-svg-to-png

You'll need to have at least Node.js 8 or newer.

If you want to use the command line interface you'll most likely want to install it globally so that you can run convert-svg-to-png from anywhere:

$ npm install --global convert-svg-to-png

CLI

Usage: convert-svg-to-png [options] [files...]


  Options:

    -V, --version          output the version number
    --no-color             disables color output
    --background <color>   specify background color for transparent regions in SVG
    --base-url <url>       specify base URL to use for all relative URLs in SVG
    --filename <filename>  specify filename for the PNG output when processing STDIN
    --height <value>       specify height for PNG
    --puppeteer <json>     specify a json object for puppeteer.launch options
    --scale <value>        specify scale to apply to dimensions [1]
    --width <value>        specify width for PNG
    -h, --help             output usage information

The CLI can be used in the following ways:

• Pass SVG files to be converted to PNG files as command arguments
  • A glob pattern can be passed
  • Each converted SVG file will result in a corresponding PNG with the same base file name (e.g. image.svg -> image.png)
• Pipe SVG buffer to be converted to PNG to command via STDIN
  • If the --filename option is passed, the PNG will be written to a file resolved using its value
  • Otherwise, the PNG will be streamed to STDOUT

API

convert(input[, options])

Converts the specified input SVG into a PNG using the options provided via a headless Chromium instance.

input can either be a SVG buffer or string.

If the width and/or height cannot be derived from input then they must be provided via their corresponding options. This method attempts to derive the dimensions from input via any width/height attributes or its calculated viewBox attribute.

This method is resolved with the PNG output buffer.

An error will occur if both the baseFile and baseUrl options have been provided, input does not contain an SVG element or no width and/or height options were provided and this information could not be derived from input.

Options

| Option | Type | Default | Description | | ------------ | ------------- | ----------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- | | background | String | N/A | Background color to be used to fill transparent regions within the SVG. Will remain transparent if omitted. | | baseFile | String | N/A | Path of the file to be converted into a file URL to use for all relative URLs contained within the SVG. Cannot be used in conjunction with the baseUrl option. | | baseUrl | String | "file:///path/to/cwd" | Base URL to use for all relative URLs contained within the SVG. Cannot be used in conjunction with the baseFile option. | | height | Number/String | N/A | Height of the output to be generated. Derived from SVG input if omitted. | | puppeteer | Object | N/A | Options that are to be passed directly to puppeteer.launch when creating the Browser instance. | | scale | Number | 1 | Scale to be applied to the width and height (specified as options or derived). | | width | Number/String | N/A | Width of the output to be generated. Derived from SVG input if omitted. |

The puppeteer option is not available when calling this method on a Converter instance created using createConverter.

Example

const { convert } = require("convert-svg-to-png");
const express = require("express");

const app = express();

app.post("/convert", async (req, res) => {
  const png = await convert(req.body);

  res.set("Content-Type", "image/png");
  res.send(png);
});

app.listen(3000);

convertFile(inputFilePath[, options])

Converts the SVG file at the specified path into a PNG using the options provided and writes it to the output file.

The output file is derived from inputFilePath unless the outputFilePath option is specified.

If the width and/or height cannot be derived from the input file then they must be provided via their corresponding options. This method attempts to derive the dimensions from the input file via any width/height attributes or its calculated viewBox attribute.

This method is resolved with the path of the PNG output file for reference.

An error will occur if both the baseFile and baseUrl options have been provided, the input file does not contain an SVG element, no width and/or height options were provided and this information could not be derived from input file, or a problem arises while reading the input file or writing the output file.

Options

Has the same options as the standard convert method but also supports the following additional options:

| Option | Type | Default | Description | | ---------------- | ------ | ------- | ------------------------------------------------------------------------------------------------------- | | outputFilePath | String | N/A | Path of the file to which the PNG output should be written to. Derived from input file path if omitted. |

Example

const { convertFile } = require("convert-svg-to-png");

(async () => {
  const inputFilePath = "/path/to/my-image.svg";
  const outputFilePath = await convertFile(inputFilePath);

  console.log(outputFilePath);
  //=> "/path/to/my-image.png"
})();

createConverter([options])

Creates an instance of Converter using the options provided.

It is important to note that, after the first time either Converter#convert or Converter#convertFile are called, a headless Chromium instance will remain open until Converter#destroy is called. This is done automatically when using the API convert methods, however, when using Converter directly, it is the responsibility of the caller. Due to the fact that creating browser instances is expensive, this level of control allows callers to reuse a browser for multiple conversions. It's not recommended to keep an instance around for too long, as it will use up resources.

Options

| Option | Type | Default | Description | | ----------- | ------ | ------- | -------------------------------------------------------------------------------------------------- | | puppeteer | Object | N/A | Options that are to be passed directly to puppeteer.launch when creating the Browser instance. |

Example

const { createConverter } = require("convert-svg-to-png");
const fs = require("fs");
const util = require("util");

const readdir = util.promisify(fs.readdir);

async function convertSvgFiles(dirPath) {
  const converter = createConverter();

  try {
    const filePaths = await readdir(dirPath);

    for (const filePath of filePaths) {
      await converter.convertFile(filePath);
    }
  } finally {
    await converter.destroy();
  }
}

Other Formats

If you would like to convert a SVG into a format other than PNG, check out our other converter packages below:

https://github.com/neocotic/convert-svg

Bugs

If you have any problems with this package or would like to see changes currently in development you can do so here.

Contributors

If you want to contribute, you're a legend! Information on how you can do so can be found in CONTRIBUTING.md. We want your suggestions and pull requests!

A list of all contributors can be found in AUTHORS.md.

License

Copyright © 2018 Alasdair Mercer

See LICENSE.md for more information on our MIT license.