Warp iMagick Image Optimization. Resize & Compress images. Sharpen & Optimize images. Convert WebP.


  • Warp iMagick Image Compressor enables your site to serve images in next-gen formats.
    JPEG/PNG media types are converted to WebP clones. Original images are optimized & served for compatibility with older ( not WebP compatible ) browsers.

  • Warp iMagick Image Optimizer is private and free.
    No external cloud/service or signup required. No limits in number or megabytes of optimized images. Plugin uses only PHP software installed on your server.

  • Warp iMagick Image Optimization is easy to use.
    Install, activate, configure and start uploading new media images. To bulk (re)compress existing media images use “Regenerate Thumbnails Plugin” or “WP CLI media regenerate” command.

  • After activation, settings you may want to change are JPEG Compression Quality and SharpenImage Sigma.
    Choose your image compress quality from 30% to 95%. As recommended in video below, plugin default JPEG Compression Quality of 60% is good speed/quality compromise for most of the web sites. If not, choose your own best compression/quality settings. Sharpen Image from 0.5 to 1.5 Sigma. For the rest of the settings, use defaults (some recommended by Google) or feel free to experiment and have fun with. 😇

  • You don’t have to resize or optimize images before upload.
    Warp iMagick image optimizer plugin will do it for you and preserve your uploaded high quality original image as source for multiple recompressions without ever over-compressing.

  • Fastest and most comprehensive serving of converted WebP images …
    … is achieved by your server software (not by PHP). Transparent serving WebP clones instead original JPEG/PNG uploads (for WebP enabled browsers) covers all image links: in HTML code, in CSS code (styles) and in JavaScript code. You do not have to rewrite HTML , nor your (background image) CSS styles, nor dynamically invoked images via Java Script. Serving WebP images with Apache Server requires simple manual (DIY) modification of .htaccess file. Use WP Htaccess Editor Plugin to safely modify (copy&paste) your Apache .htaccess configuration file. You will find instructions on how to configure server and deliver WebP images on the settings page. Click on HELP at the top right of the plugin SETTINGS PAGE. If you use WordOps – Free WordPress sites Nginx stack & control CLI for VPS or Dedicated servers), your Nginx Server is already configured to serve WebP clones instead original JPEG/PNG uploads & subsizes/thumbnails, but restricted to “wp-content/uploads/” directory only.

  • Improve your site performance, Google PageSpeed score and SEO ranking …
    … by serving better compressed images (JPEG/PNG/WebP). When generating WebP images is enabled, every JPEG and PNG media image or thumbnail found during image optimization process is converted to WebP and saved as copy with .webp extension added. Default PNG&JPEG to WebP image compression quality is 75% (configurable). In addition, JPEG to WebP compression quality can be set to use & follow compression quality set for JPEG images.

  • Automatic image optimization to subsizes/thumbnails and conversion to WebP images:
    Compress image files more or keep higher image quality than WordPress image optimization does by default. Compress images automatically on upload or on “regenerate thumbnails”. Uploaded image is always preserved in original state. Image Compression will always start from original image quality. You can’t “overoptimize” or “overcompress”. Reoptimize existing images with “Regenerate Thumbnails plugin” single or batch process, or with “WP CLI media regenerate” command.

  • Generating WebP images is optional
    JPEG image optimization is speed & pagespeed/SEO score efficient even without WebP. Because plugin has advanced JPEG image compression capabilities, not available in WordPress original image optimization.

  • Image optimization is compatible with “WP CLI media regenerate” command and/or with “Regenerate Thumbnails” plugin.
    Important Note: Since WordPress 5.3, BIG JPEG images reduced to 2560×2560 (by “Big Image Size Threshold” feature) and then manually edited by user, on regenerate, will be restored back to original (unedited) version. User edited modifications will be lost, unless this plugin is used. See GitHub issue. Same bug/issue applies both to “WP CLI media regenerate” command and “Regenerate Thumbnails plugin”. To fix that bug/issue, install or upgrade Warp iMagick plugin to version 1.6.2 or above.

  • Compatible up to PHP 8.1.* and tested against WP & PHP 7.4 coding standards.
    Tested with PHP_CodeSniffer (phpcs) using WordPress Coding Standards GitHub rules and PHPCompatibility rules.

  • Warp iMagick Image Optimizer gives you full control over image optimization, compression quality and file size.
    Images optimization is customizable with advanced image optimization & compression settings. See all options used to optimize images in the plugin Settings page.

  • Multisite support
    Designed to work on WP multisite. No known reason to fail on WP multisite, but not extensively tested yet!

  • Clean uninstall
    By default, no plugin settings are left in your database after uninstall. Feel free to install and activate to make a trial. However, you can choose to preserve plugin options after uninstall. For detailed uninstall info related to added WebP images, see the FAQ section below.

  • Privacy
    Warp iMagick Image Compressor plugin does not collect nor send any identifiable data from your server, without your consent. WordPress cookies are used to store admin-settings page-state.

  • Known conflicts
    Due to use of bfi_thumb library which completely takes over wordpress WP_Image_Editor classes, in Ajax Search Lite plugin and in Circles Gallery plugin, Warp iMagick plugin may fail to activate while those plugins are active. Activating those plugins after Warp iMagick is activated, may cause malfunction.
    Plugin WP Email Users (tested with version 1.7.6.) causes fatal submit error when saving Warp-iMagick settings.


  • Option: JPEG Compression Quality.
    Select JPEG compression quality from 30% to 85%. Current WordPress default is 82%. [Lossy Compression].

  • Option: JPEG Compression Type.
    Select WordPress Default or Imagick Default. [Lossy Compression].

  • Option: JPEG Colorspace Transform.
    Select WordPress Default or sRGB*. Default sRGB colorspace is a World Wide Web Standard. [Lossless Color Compression]

  • Option: JPEG Color Sampling Factors.
    Select WordPress Default, 4:1:0, 4:1:1, 4:2:0*, 4:2:1, 4:2:2, 4:4:0, 4:4:1, 4:4:4. [Lossy Color Compression].

  • Option: JPEG Interlace Scheme.
    Select WordPress Default, Imagick Default, No Interlace, Progressive or Auto Select: Compare “No Interlace” with “Progressive” file size and save smaller file to the disk. [Lossless Compression].

  • Option: PNG Color Reduction.
    Enable to quantize PNG Colors into range between 16 and 1024 colors. [Lossy Color Compression].

  • Option: PNG Color Dithering.
    Enable Color Dithering to improve color transition quality (except transparent & less-than-257-colors). [Lossy Compression].

  • Option: PNG Max Number of Colors.
    Select maximal number of PNG colors. Images reduced to less than 257 colors are automatically converted to PNG Color Palette. [Lossy Color Compression].

  • Automatic: PNG Compression.
    WordPress Default and Imagick Default compression strategies are compared and smaller file size is written to disk. [Lossless Compression].

  • Option: Strip Metadata.
    Select WordPress Default settings, force WP Default Off, force WP Default On, Strip All Metadata* (on JPEG: only if colorspace is sRGB, else uses WP strip metadata). [Lossless Compression].

  • Option: WebP Conversion.
    Enable to automatically generate optimized WebP versions of JPEG and PNG images & subsizes/thumbnails. See the Settings page Help on how about to configure server.

  • Option: WebP Compression Quality.
    Select PNG & JPEG to WebP image compression quality (default 75%). In addition, JPEG to WebP compression quality can be set to use & follow compression quality set for JPEG images.

  • Option: Disable big image size threshold (JPEG only – Since WP 5.3)
    Disable WordPress big image size threshold which proportionally resizes large upload/original images to maximum frame of 2560×2560 pixels.

  • Option: Configure big image size threshold in pixels (JPEG only – Since WP 5.3)
    Configure WordPress big image size threshold frame WxH in pixels. Original is preserved, not saving disk space.

  • Option: Disable (maybe) Rotate Image (JPEG only – Since WP 5.3)
    Disable WordPress automatic image rotate when image orientation is set and not equal to 1.

  • Option: Disable generate compressed version of original image
    Disable generate (and attach) compressed version of upload/original image size.

  • Option: Enable & Reduce Upload Image Maximum Width & Height
    Enable proportional downsizing of large upload/original images over maximum width in pixels. Original upload image is resized and replaced, saving some disk space.

  • Option: Configure Upload Image Maximum Width in Pixels
    Configure maximum width for proportional downsizing of large original/upload images, in pixels. Original upload image is resized and replaced, saving some disk space.




  • JPEG Settings
  • PNG Settings
  • WebP Settings
  • Other Settings
  • Regenerate Thumbnails
  • WebP Mobile Page Score


Using The WordPress Plugin Repository

  1. Navigate to the ‘Plugins’ -> ‘Add New’ .
  2. Search for ‘Warp iMagick’.
  3. Select and click ‘Install Now’.
  4. Activate the plugin.


Where is the “GO” button?

There is no “GO” button. When activated, plugin automatically applies compression on all new JPEG/PNG media uploads.

How do I “bulk compress”?

To bulk (re)compress existing media images use “Regenerate Thumbnails Plugin” or “WP CLI media regenerate” command.

Do I need to keep ‘Regenerate Thumbnails’ plugin?

You don’t have to keep “Regenerate Thumbnails Plugin” plugin installed.

Does this plugin support WooCommerce images?

All image subsizes are supported, including any theme and/or WooCommerce specific image subsizes.

How to serve converted WebP images?

On the settings page, you will find instructions on how to configure server to redirect *.jpg/*.png to *.jpg.webp/*.png.webp and to deliver converted WebP images, if such image is generated by this plugin (file exists) and if visitor’s browser suports WebP image format. Click on HELP at the top right of the plugin SETTINGS PAGE.

How to modify Apache .htaccess configuration file?

Use WP Htaccess Editor Plugin to safely modify your Apache .htaccess configuration file.

Which PHP extensions are required by this plugin?

  1. PHP-Imagick to compress JPEG/PNG files (required).
  2. PHP-GD to convert JPEG/PNG to WebP files (optional, but usually installed).

In order to modify/resize/crop photos or images, WordPress requires at least PHP-GD. When both extensions are installed, WordPress prefers PHP-Imagick over PHP-GD.

Do I have both required PHP extensions installed?

  1. WordPress 5.2 and above: Administrator: Menu -> Tools -> Site Health -> Info -> Expand “Media Handling” and check if “ImageMagick version string” and “GD version” have values.
  2. WordPress 5.1 and below: Install Health Check & Troubleshooting plugin. Open “Health Check” plugin page and click on “PHP Information” tab. You will find there all PHP extensions installed and enabled. Search (Ctrl-F) on page for “Imagick” and “GD”.
  3. WordPress Editor class must be WP_Image_Editor_Imagick (or Warp_Image_Editor_Imagick) but NOT WP_Image_Editor_GD.
  4. PHP-Imagick extension must be linked with ImageMagick library version 6.3.2 or newer.
  5. PHP-GD extension version must be at least 2.0.0 to be accepted by WordPress Image Editor.

Does my web hosting service provide PHP-Imagick and PHP-GD extensions?

There is no excuse for hosting service providers not to allow or provide essential, free and open source PHP extensions. Both extensions are used by WordPress PHP code generating image subsizes and thumbnails!

See: WordPress recommended PHP extensions

  1. EasyWP : Yes, documentation page provided.
  2. Hostpapa : Yes, in cPanel. But may be not available in your hosting plan.
  3. WPEngine : Supposedly yes, but no web kb/help or documentation page found at the time of this version release.
  4. DreamHost : Supposedly yes, but no web kb/help or documentation page found at the time of this version release.
  5. A2 Hosting: Supposedly yes, but no web kb/help or documentation page found at the time of this version release.
  6. Ask your host-service provider support.

How to install missing PHP-Imagick and PHP-GD extensions?

  1. cPanel based hosting: Configuration may be not available in your hosting plan.
  2. Debian/Ubuntu using ssh access: Via root user console, or prepend sudo to “apt install php-imagick php-gd”.
  3. CentOS/RHEL/Fedora using ssh access: “yum install php-imagick php-gd”.
  4. Ask your host-service provider support.

Why WebP files have two extensions?

To prevent overwriting duplicate “WebP” files. With single extension, when you upload “image.png” and “image.jpg”, second “image.webp” would overwrite previous one.

Why is WebP setting (checkbox) disabled?

Because your server has no PHP-GD graphic editing extension or your PHP-GD extension has no WebP support.

What happens with images when plugin is deactivated or deleted?

  1. Existing images remain optimized. If you run “Regenerate Thumbnails” batch process, after plugin is deactivated or deleted, batch process will restore original file-size and quality of WordPress thumbnails.
  2. If you have WebP images, they won’t be deleted. You can delete all WebP images while plugin is active. To delete WebP images, disable WebP option and then batch-run “Regenerate Thumbnails” for all media images.

Why is plugin disabled or fails to activate?

Because your server has no PHP-Imagick extension installed or has too old version of PHP-Imagick.


December 3, 2021
Have been using it on FreeBSD, working perfectly with PHP 8 and ImageMagick 7. Thanks for such a great tool!
May 7, 2021
Not only the plugin does what it claims the right way (no dependency to cloud services) but the developer is also very responsive. Kudos.
April 28, 2021
This plugin helps enhance WordPress' default image optimizing if your server is using Imagick (which is preferable to GD if quality is important). There are enough options to dial it in for your particular needs, and the authors continue to add the right options as needs arise. The one option that is very unique compared to most image optimization plugins is the ability to add sharpening to the resized thumbnails. By default, WordPress does not really sharpen the different smaller 'thumbnail' images it creates every time you upload an image. This is VERY important if you value sharp, quality images, as downsampling images can make them look very soft (this is why Photoshop can automatically sharpen when downsampling). This feature alone is a game-changer for us! Lastly, the plugin authors are very responsive and helpful, and seem to care about doing things properly.
Read all 10 reviews

Contributors & Developers

“Warp iMagick Image Optimization. Resize & Compress images. Sharpen & Optimize images. Convert WebP.” is open source software. The following people have contributed to this plugin.



Current Version

  • Tested with WP 5.9-beta3
  • Handle missing php module.
  • Update remainder (Ignore Easy updates manager)

Previous versions