A wrapper around Sharp, providing an easy to use interface to make Sharp usable in a front-end development workflow.

Usage no npm install needed!

<script type="module">
  import mischbackImp from 'https://cdn.skypack.dev/@mischback/imp';



npm (scoped) install size

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ImP is the abbreviation of image processor. Basically it is a wrapper around the wonderful Sharp module, providing an easy to use interface to make Sharp usable in a front-end development workflow.


Just install ImP from npm:

npm install --save-dev @mischback/imp

Most likely you will want to install it as a development dependency for internal usage (see below for Security Considerations).


After installation, ImP is available using the following command:

npx imp

Please note, that a configuration file is required, see below for configuration options and command line parameters.

A more sophisticated usage example is provided in the advanced usage guide.


ImP is configured by its configuration file and command line parameters. Providing a configuration file (or the corresponding key in package.json) is mandatory, as the TargetConfig and FormatConfig can not be specified by command line.

The in-depth description of the configuration file is provided in the configuration guide.

Configuration File

ImP uses cosmiconfig to retrieve and read the configuration file.

The following locations are searched:

  • key "imp" in package.json
  • an extensionless "rc file", in YAML or JSON format: .imprc
  • an "rc file" with extension: .imprc.json, .imprc.yaml, .imprc.yml, .imprc.js or .imprc.cjs
  • a .config.js or .config.cjs CommonJS module

The listed filenames/locations are checked in the current working directory and then the search is continued upwards (see cosmiconfig's README for further details).

Configuration by Command Line

Additionally, ImP accepts the following command line parameters:

  • --debug, -d: Activate the debug mode; in this mode, cosmiconfig's caching is cleared and additional log messages are emitted;
  • --configFile, -c: Specify another name/location for the configuration file to be used;
  • --inputFile, -i: Specify the name/location of the image to be processed. This option may be specified multiple times;
  • --outputDir, -o: Specify the directory to write the processed images to;
  • --quiet, -q: Suppress all output.

Please note that providing --inputFile and --outputDir through command line parameters will overwrite the corresponding parameter in the configuration file.

Security Considerations

ImP was developed without any special regard to security. It is assumed to be used in a safe environment, meaning that input and output are under strict of the user.

You should not expose ImP publicly, at least not without some wrapper that does perform sanitarization of any user input.

What about this crazy install size?

ImP is a wrapper around Sharp, which is in fact a very capable interface to libvips itsself.

The install size actually reflects the installation of libvips.


Issues, pull requests and feature requests are welcome. Just use the project's issue tracker.

ImP is implemented in TypeScript and compiled/transpiled to actual JavaScript on release.

More details about the internal guidelines regarding code formatting, linting, testing and releasing are provided in docs/.