On what kinds of web pages will I see the most benefit from using WP QuickDraw?

WP QuickDraw will work well on any WordPress website, but it is particularly well suited for image-heavy pages such as a photo gallery, product listing page on an e-commerce store, photography blog, or image sharing forum. Generally, the more images you have on your website, the greater the benefit you will receive from WP QuickDraw.


Images account for 59% of site payload on average.

Image optimization offers the most significant byte savings and performance improvements for your website. The smaller a website’s payload, the faster a browser can download and render useful content on the screen. With WP QuickDraw, your site will load faster and the layout will jump around less.

Does WP QuickDraw work with caching plugins, such as W3 Total Cache?

Yes; in fact, we recommend it for optimal performance!

WP QuickDraw works by asynchronously loading images on a webpage through JavaScript, so its functionality does not interfere with a full-page cache. We have tested WP QuickDraw with W3 Total Cache, WP Rocket, WP Super Cache, and other popular caching plugins for WordPress.

Read more about WP QuickDraw and caching plugins here »

Will WP QuickDraw work if my website’s images are served through a CDN (Content Delivery Network)?

Yes, as long as the images are uploaded through the WordPress Media Library. We’ve explicitly tested CDN uploads using W3 Total Cache, WP Rocket, and WP Super Cache. Compatibility with popular CDN plugins is currently only available in WP QuickDraw PRO.

What are the requirements for WP QuickDraw?

WP QuickDraw works with nearly all WordPress installs and 99.9% of the images in use on the internet. WP QuickDraw requires the GD or ImageMagick image library and DOM extension for PHP, which are installed by default on most servers.

WP QuickDraw & WP QuickDraw PRO require:

  • WordPress Version: 3.2+
  • PHP Version: 5.5+
  • PHP must be configured with GD (included with PHP, but not enabled by default. Very commonly enabled on WordPress hosts.)
  • Browsers (tested): IE11, Edge 16+, Firefox 59+, Chrome 64+, Safari 11+
  • PHP Memory (WP QuickDraw PRO only): PHP configured with at least 128M memory via memory_limit directive. This is the default PHP memory limit in recent versions, but it can be changed.

Does WP QuickDraw work on non-WordPress sites?

No. WP QuickDraw is a WordPress plugin, so it will not work on sites that do not use WordPress as their primary CMS.

I see a WP Cron capability error message. How do I resolve it?

WP QuickDraw utilizes the WordPress cron (WP Cron) to generate image sets for each of your WPQD-enabled images as a background process. When you activate the plugin, it will run a compatibility check to verify that WP Cron is enabled and working properly on your website. If the compatibility check fails, you will see an error message at the top of your admin panel screen. Here are some of the most common error messages and how you can address them:


ERROR: WP Cron is disabled. Please enable WP Cron so that image generation can proceed.

This means that the constant DISABLE_WP_CRON is set to TRUE on your WordPress installation. Most likely this will be defined in your wp-config.php file. Check your wp-config.php file and delete this line: define(‘DISABLE_WP_CRON’, true); If you don’t see this in your wp-config.php, it may be defined elsewhere, such as within a plugin you’ve installed.


ERROR: Unexpected HTTP response code “401” from wp-cron.php. WP Cron must be running properly for image generation to proceed.

An HTTP 401 response means “unauthorized” and likely indicates that there is basic HTTP authentication enabled on your website. You can define an exception so that HTTP authentication is disabled only for the wp-cron.php file. If your web server is running Apache, insert the following into the .htaccess file in the root directory for your WordPress installation:

<files wp-cron.php>
   Order Allow,Deny
   Allow from all
   Satisfy any


ERROR: Unexpected HTTP response code “404” from wp-cron.php. WP Cron must be running properly for image generation to proceed.

An HTTP 404 response means “not found”. Look in the root directory for your WordPress installation and verify that the “wp-cron.php” file exists. If it does exist, there may be an issue with the way URL rewrites are implemented on your website. Check your .htaccess or nginx.conf file.

Can I use the single site PRO license on development or staging versions of my site?

Yes, you can. If your development or staging website URL adheres to one of the following patterns, you can use your production credentials to activate your license on that site as well.

If you buy a license for www.domain.com or domain.com, the following URLs are also licensed:

  • dev.domain.com
  • development.domain.com
  • staging.domain.com
  • www.domain.local
  • local.domain.com

How do I request a refund using your money back guarantee?

While we also offer a trial version of WP QuickDraw PRO, we offer a 30-day money back guarantee on the purchase of a PRO license. If you’re not satisfied with WP QuickDraw PRO in the first thirty days, you’re fully protected by our no-questions-asked money back guarantee. Although we don’t think you’ll ever want one, we’ll gladly provide a refund if it’s requested within 30 days of purchase. With our 30 day refund policy you can buy with confidence. Click here to request a refund.

Can I temporarily disable WP QuickDraw on a single page without disabling it site-wide?

Yes! For the purposes of testing the speed boost you get with WP QuickDraw, you can view any WordPress URL with WP QuickDraw disabled by simply appending ?wpqd=off to the URL (e.g. http://www.your-website.com/page-slug?wpqd=off).

If you’d like to more permanently disable WP QuickDraw for a specific page, you can check the ‘Disable WP QuickDraw on this page’ checkbox found on the righthand column of the page edit screen.

Can I disable certain images from being loaded with WP QuickDraw?

Yes! You can disable WP QuickDraw on specific images site-wide or only for a specific page. To disable WP QuickDraw on an image site-wide, Once you have enabled the plugin, you will see a checkbox on the “Attachment Details” edit screen (in the Media Library section of WP Admin) which allows you to enable or disable WP QuickDraw on a per image basis.

To disable WP QuickDraw for an image just on a single specific page, you can ‘edit’ that image from the WordPress page editor image dialog and then check the “Disable WPQD for this image on this page” setting checkbox. Alternatively, you can add the CSS class wpqd-disabled to any image to tell WP QuickDraw to ignore it.

Will WP QuickDraw’s image replacement behavior interfere with SEO bot crawlers?

No. The plugin includes logic that redirects bots to a version of the page without WP QuickDraw enabled, so crawlers will only see the unmodified HTML output.

Can I use WP QuickDraw to load CSS background images or with a JavaScript image slider/carousel?

No. At this time, only images included on a page through HTML <img> tags are supported. Simpler image carousels that use the image HTML element do integrate with WP QuickDraw.

Will I see progressive loading in the WP Admin edit screen?

No, but you will in preview mode and on the front-end of your site!

Does WP QuickDraw alter the images being displayed on my site?

Sometimes. In order for the Progressive PNG algorithm to work, image width and height values must be divisible by eight. When an image is initially processed by WP QuickDraw Pro, up to seven pixels may be cropped from the outside of the image to ensure that the image dimension is divisible by eight.

In our testing, the removal of a handful of pixels from the outside of the image rarely impacted page display or layout. In instances where the removal of a small number of pixels does affect page layout (e.g., a 1px border is hardcoded into the outer edge of an image), the layout styles can be recreated using best practices (e.g., a 1px border can be applied using CSS) or WP QuickDraw can easily be turned off for that specific image.

I am having trouble installing or using WP QuickDraw PRO on my website. Will you help me?

Yes! Please reach out to us on our Support Forums (accessible to users with an active PRO license subscription), and we will do our best to assist you.