Easily Optimize WordPress Images Using WP CLI and Some Binaries
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Easily optimize images using WP CLI.

WP CLI wrapper for spatie/image-optimizer. Optimizing gif, jpeg, jpg, png, svg, webp images by running them through a chain of various image optimization tools. Check this project's introductory blog post about why I built it.


# optimize specific attachments
$ wp image-optimize attachment 123 223 323

# optimize certain number of attachments
$ wp image-optimize batch --limit=20

# restore the full sized images of specific attachments
$ wp image-optimize restore 123 223 323
$ wp media regenerate 123 223 323

# restore all full sized images and drop all meta flags
$ wp image-optimize reset
$ wp media regenerate

# Find and optimize images under a given directory **without backup**
$ wp image-optimize find /path/to/my/directory --extensions=gif,jpeg,jpg,png,svg,webp

# shortcusts for `wp image-optimize find` **without backup**
$ wp image-optimize mu-plugins
$ wp image-optimize plugins
$ wp image-optimize themes
$ wp image-optimize wp-admin
$ wp image-optimize wp-includes

# learn more
$ wp help image-optimize
$ wp help image-optimize <subcommand>


  • PHP v7.2 or later
  • WP-CLI v2.3.0 or greater

Since wp-cli/wp-cli-bundle bundles an older version of symfony/process which incompatible with spatie/image-optimizer, WP-CLI must be installed via composer.


$ wp package install typisttech/image-optimize-command:@stable

Optimization tools

Under the hood, image-optimize-command invokes spatie/image-optimizer which requires these binaries installed:

Check spatie/image-optimizer's readme for install instructions.

Note that spatie/image-optimizer only supports Pngquant 2.5 and lower. See: spatie/image-optimizer #97 and #99.

SVGO and cwebp are optional

Note that WordPress doesn't support svg files out of the box. You can omit SVGO. However, if you have enabled WordPress svg support and uploaded svg files to WordPress media library, you must install SVGO. Otherwise, the command will fail.

Same goes to cwebp.

Use Cases

First use

This command optimize both the full sized image(the one you uploaded) and the thumbnails(WordPress auto-resize these images for you).

Chances are the thumbnails are missing or never generated:

  • theme switched after upload
  • plugins activated after upload
  • deleted the images from disk but not updated WordPress' database

Simplest solution is to regenerate thumbnails then optimize:

$ wp media regenerate
$ wp image-optimize batch --limit=9999999

$ wp image-optimize mu-plugins
$ wp image-optimize plugins
$ wp image-optimize themes
$ wp image-optimize wp-admin
$ wp image-optimize wp-includes

After upgrading WordPress core / plugins / themes

$ wp image-optimize mu-plugins
$ wp image-optimize plugins
$ wp image-optimize themes
$ wp image-optimize wp-admin
$ wp image-optimize wp-includes

Restoring the originals

This command backs up the full sized images before optimizing attachments. If you want to restore them:

# optimize
$ wp image-optimize attachment 123

# restore the full sized image
$ wp image-optimize restore 123
# regenerate the thumbnails from the original full sized image
$ wp media regenerate 123

Migrating from image-optimize-command v0.1.x

Starting from v0.2, this command backs up the full sized images before optimizing attachments. To migrate from image-optimize-command v0.1.x:

$ wp image-optimize reset
$ wp media regenerate
$ wp image-optimize batch --limit=9999999


What kind of optimization it does?

Mostly applying compression, removing metadata and reducing the number of colors to gif, jpeg, jpg, png, svg, webp images. The package is smart enough pick the right tool for the right image.

Check Freek Van der Herten's article explaining spatie/image-optimizer's sane default configuration.

How to customize the optimization?

use Spatie\ImageOptimizer\OptimizerChain;

add_filter('TypistTech/ImageOptimizeCommand/OptimizerChain', function (OptimizerChain $optimizerChain): OptimizerChain {
    // Option A: Send messages to $optimizerChain.

    // Option B: Make a new $optimizerChain.
    // See: https://github.com/spatie/image-optimizer/blob/master/src/OptimizerChainFactory.php
    $optimizerChain = new OptimizerChain();

    // Finally
    return $optimizerChain;

How to skip backups / restorations?

:warning: The optimzation is lossy. If you skip backing up the original files, there is no way to recover the original files. Proceed with caution.

use TypistTech\ImageOptimizeCommand\Operations\AttachmentImages\Backup; use TypistTech\ImageOptimizeCommand\Operations\AttachmentImages\Restore; add_filter('TypistTech/ImageOptimizeCommand/Operations/AttachmentImages/Backup', function (): Backup { // TODO: You have to implement a null backup class. return $myNullBackupObject; }); add_filter('TypistTech/ImageOptimizeCommand/Operations/AttachmentImages/Restore', function (): Restore { // TODO: You have to implement a null restore class. return $myNullRestoreObject; });

It would be nice to have those 2 null operations in a separate package. Submit pull requests to mention it in this readme if you have implemented it.

Does running wp image-optimize attachment / batch multiple times trigger multiple optimization for the same attachments?


By default, boolean flags (meta fields) are given to attachments after optimization. This is to prevent re-optimizing an already optimized attachment. If you changed the image files (e.g.: resize / regenerate thumbnail), you must first reset their meta flags.

Note: The find subcommand and its shortcuts don't create meta flags.

Will the images look different after optimization?

Yes, a little bit. This is lossy optimization. However, you won't notice the difference unless you have a trained eye for that.

See spatie/image-optimizer's readme on binary options used.

Why my GIFs stopped animating?

When you upload an image using the media uploader, WordPress automatically creates several copies of that image in different sizes...When creating new image sizes for animated GIFs, WordPress ends up saving only the first frame of the GIF...

--- wpbeginner

Luckily for you, Lasse M. Tvedt showed how to stop WordPress from resizing GIFs on StackExchange.

Can I use this on managed hosting?

No, you can't use this on managed hosting such as Kinsta, Flywheel or WP Engine because they prohibit installing the binaries.

If you must use it on managed hosting, hire a developer to add SaaS provider integration:

Do I have to install SVGO or cwebp?

No, if you don't have any svg files in WordPress media library.

Yes, if you have:

Same goes to cwebp.

PHP Fatal error: Allowed memory size of 999999 bytes exhausted (tried to allocate 99 bytes)

This is a common WP CLI issue. See: https://bit.ly/wpclimem

Does it have a limits or quotas?

No, unlike other SaaS alternatives, this package runs on your server without any limitation on file sizes or a monthly quota. Totally free of charge.

Is it for everyone?

No, it comes at a cost. Optimization is CPU intensive. Expect CPU usage rockets up to 100% during optimization. Schedule it to run at late night in small batches.

Learn more on this article.

Will you add support for older PHP versions?

Never! This plugin will only work on actively supported PHP versions.

Don't use it on end of life or security fixes only PHP versions.

It looks awesome. Where can I find some more goodies like this?

Where can I give :star::star::star::star::star: reviews?

Thanks! Glad you like it. It's important to let my know somebody is using this project. Since this is not hosted on wordpress.org, please consider:

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Why don't you hire me?

Ready to take freelance WordPress jobs. Contact me via the contact form here or, via email [email protected]

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Contact: Tang Rufus

Running the Tests

Run the tests:

$ composer test
$ composer style:check


Please provide feedback! We want to make this library useful in as many projects as possible. Please submit an issue and point out what you do and don't like, or fork the project and make suggestions. No issue is too small.

Change log

Please see CHANGELOG for more information on what has changed recently.


If you discover any security related issues, please email [email protected] instead of using the issue tracker.


image-optimize-command is a Typist Tech project and maintained by Tang Rufus, freelance developer for hire.

Full list of contributors can be found here.

Special thanks to Freek Van der Herten whose spatie/image-optimizer package makes this project possible.


The MIT License (MIT). Please see License File for more information.