While other image optimization tools are available from the command line, ImageOptim-CLI exists because the current benchmarks suggest that ImageOptim, ImageAlpha and JPEGmini currently outperform those alternatives over lossless and lossy optimizations.
Check out this short video demo of ImageOptim-CLI to see how it works.
Jamie Mason / @fold_left.
- Related projects
ImageOptim-CLI is written in Shell and AppleScript, you don't need Node.js to run it. npm is suggested because it makes installation very convenient.
npm install -g imageoptim-cli
You can install manually by downloading the latest zip then adding ImageOptim-CLI to your $PATH.
curl --output imageoptim-cli.zip https://codeload.github.com/JamieMason/ImageOptim-CLI/zip/1.14.8 unzip imageoptim-cli.zip export PATH=$PATH:imageoptim-cli/bin
Saving somewhere in your home directory such as
~/imageoptim-cliis recommended, but not essential. Saving to
/Applicationsis not recommended, do not do this.
JPEGmini and support for assistive devices
You may be presented with the following message the first time you run ImageOptim-CLI with the
To automate JPEGmini we need to add Terminal.app (or iTerm.app etc) to the 'support for assistive devices' whitelist.
The JPEGmini OS X Apps don't include a command line API, so a real user is simulated by entering synthetic clicks and keyboard commands instead. This requires your permission and is easily set up in System Preferences as shown by these guides.
- Enable access for assistive devices in OS X Yosemite.
- OS X Mavericks: Enable access for assistive devices and applications
Usage: imageoptim [options] Options: -d, --directory directory of images to process -a, --image-alpha pre-process PNGs with ImageAlpha.app * -j, --jpeg-mini pre-process JPGs with JPEGmini.app ** -m, --min-quality pngquant min quality parameter -s, --skip-if-larger pngquant use --skip-if-larger -q, --quit quit all apps when complete -c, --no-color disable color output -h, --help display this usage information -e, --examples display some example commands and uses -v, --version display the version number --verbose display detailed, per-file info on optimizations * http://pngmini.com ** https://itunes.apple.com/us/app/jpegmini/id498944723
Optimise a directory of images
This command will optimise all image files in your Awesome project.
imageoptim --directory ~/Sites/Awesome # [options]
Optimise a filtered set of images
This command will optimise just the .jpg files in your Awesome project.
find ~/Sites/Awesome -name '*.jpg' | imageoptim # [options]
Passing additional options
The long format for enabling options is as follows;
imageoptim --jpeg-mini --image-alpha --quit --no-color --directory path/to/images
The equivalent of the above in short format is as follows;
imageoptim -j -a -q -d -c path/to/images
Adding to git pre-commit hook
Adding the below to your_project/.git/hooks/pre-commit will run imageoptim-CLI each time you commit new and changed files into your project. Any files which aren't images will be ignored.
images=$(git diff --exit-code --cached --name-only --diff-filter=ACM -- '*.png' '*.jpg') $(exit $?) || (echo "$images" | imageoptim && git add $images)
Comparison of image optimization tools
ImageOptim-CLI features in this comparison of the performance of image optimisation tools alongside Kraken.io, CodeKit, grunt-contrib-imagemin, Smush.it, and TinyPNG.
Article for Smashing Magazine
The ImageOptim-CLI Workflow for Alfred app is alfred-image-optim-workflow
Do ImageOptim, ImageAlpha, or JPEGmini come bundled with the ImageOptim-CLI installation?
You will need to install these applications separately.
Do I have to pay to use ImageOptim-CLI?
The CLI, ImageOptim and ImageAlpha are all free. JPEGmini is a paid-for product but you can use ImageOptim-CLI and choose not to run JPEGmini.
Why are shorthand options supplied in the format
imageoptim -a -j -q instead of the more common
This was an early mistake which now needs supporting for backwards compatibility.
Issue 21 is open to add support for
-ajq format as well as the current format.
The WebP image format looks promising, can you get ImageOptim-CLI to convert images to it?
WebP looks great and may well overtake the formats handled by ImageOptim-CLI, but converting images to WebP is outside ImageOptim-CLI's chosen remit.
Can you get ImageOptim-CLI to skip images it has already processed, if they haven't changed?
JPEGmini does this today, but for ImageOptim and ImageAlpha I feel a feature like this belongs in those applications rather than this automator.
ImageOptim makes the fans on my Mac run at full power.
Optimising images is a pretty intensive process, so instead of optimising one image at a time (which would take forever) — ImageOptim optimises many images at the same time until all of them are done.
A side effect of this is that the fans come on at full power to keep your machine cool while it's maxed out.
I don't think ImageAlpha is running, I can't see anything.
ImageOptim-CLI uses ImageAlpha's internal installation of pngquant so it's normal that nothing is shown on screen.
It's also possible that if you look in the Activity Monitor
you will not see
pngquant displayed but it is being run. In my experience it's only when you
run ImageOptim-CLI on a very large number of PNGs that you have enough time to spot it.
Can I configure ImageAlpha's settings using ImageOptim-CLI?
ImageOptim-CLI is intended to be a simple, convenient, powerful, general-purpose image optimisation tool. If your needs have outgrown ImageOptim-CLI it's better to run pngquant separately, passing whatever custom settings you need.
Can I use ImageOptim-CLI with JPEGmini Lite, the free version of JPEGmini?
Not currently, the full version of JPEGmini already has some subtle differences and JPEGmini Lite causes further fragmentation. It is possible but not a priority, as the free version has a limit of processing 30 images per day anyway.
I upgraded from JPEGmini Lite to JPEGmini but ImageOptim-CLI still says JPEGmini is not installed.
Performing the in-app upgrade leaves the app named as jpegmini-lite, so ImageOptim-CLI can't determine whether it's the free or full version. It is better to instead buy the full version of JPEGmini separately.
ImageOptim-CLI says “To automate JPEGmini we need to enable GUI Scripting”, how do I do that?
See this tutorial on how to manage Accessibility preferences and GUI Scripting. In the case of OS X Mavericks, you will want to add the Applications JPEGmini and Terminal (or equivalent such as iTerm).
Windows and Linux
Can I use ImageOptim-CLI on Windows or Linux?
ImageOptim-CLI is responsible for automating 3 OS X applications so is inherently bound to OS X for that reason.
Are there any plans for ImageOptim-CLI to support Windows or Linux?
It would first require ImageOptim, ImageAlpha, and JPEGmini to be available for those platforms.