Sketch Image Compressor Plugin

A Plugin for Sketch that compresses your exported bitmap assets, to keep filesize to a minimum. This Plugin requires Sketch 3.8.

Please note that the compression is lossless, so no pixels will be harmed by running this Plugin : )

Installation

• Download Sketch Image Compressor & unzip it.
• Double click Sketch Image Compressor.sketchplugin to install the Plugin.

Usage

The Plugin uses two methods for asset compression:

• Quick Compression happens automatically, whenever you export an asset from Sketch using the File › Export… menu option or the Export button in the toolbar. The Plugin will run your PNG & JPG assets through optipng and jpegoptim using the quickest settings for both, so that you get smaller files as fast as possible.
• Full Compression happens when you choose the Plugins › Sketch Image Compressor › Export All Assets menu option. You’ll be asked for a path where your assets will be exported, and then the Plugin will export every exportable layer from your document, and run the assets through advpng, optipng, pngcrush, zopflipng, jpegtran and jpegoptim, using more aggressive settings than the Quick Compression (i.e: the operation will be extremely slow)

Please note that both methods won’t block Sketch’s UI when running, so you’ll be able to keep on working while the compressors run. However, running a Full Compression on a non-trivial document will most likely consume a lot of CPU for a long time, so don’t expect Sketch to be as snappy as usual : )

You’ll get some feedback about the process in the Sketch window while it’s running, and some stats when it is done.

Acknowledgements

• Thank you ImageOptim for the inspiration. If you’re looking for more fine-grained control of your compression settings, or a way to do lossy compression, it doesn’t get any better than this.
• Thanks to the following projects:
  • advpng
  • jpegoptim
  • jpegtran
  • optipng
  • pngcrush
  • zopflipng