Imsanity Plugin Automatically Resizes, Compresses Images in WordPress

Imsanity is my favorite plugin for resizing and compressing images that are uploaded to WordPress. It's better to resize and compress on your computer prior to uploading, but many people don't know how, or simply won't do it. So, I install Imsanity to do the job for them.

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What Can Imsanity Do?

  • Resize JPG, PNG, GIF. When it does, it replaces the original.
  • Compress JPG (but only those above dimensions you specify)
  • Compress previously uploaded images (even unattached ones)
  • Lets you specify JPG quality for compression
Imsanity settings

Why Resize and Compress?

When I train clients to use WordPress, I stress the importance of resizing and compressing images. Resizing means changing the dimensions of the image (say, from 4272 × 2848 px down to 1024 × 683 px. Compressing means removing data from an image, such as removing metadata, reducing color depth, and reducing fidelity.

  • So images and pages load quickly on slow connections (especially mobile devices)
  • A smaller total file size for the site reduces the amount of storage space taken on the host and backup destination
  • A smaller total file size for the site helps backups run quickly and smoothly.

Rules of Thumb

In general, I recommend keeping images below 250 KB whenever possible. You can use the image editor of your choice to resize and compress images before uploading them to the site. I generally resize images to a max width (for landscape) or height (for portrait) of 2048 px, and save JPEGs at 80% quality (compress them) to get them down to around 250 KB. For specific steps, see the documentation for your image editor.

Let Imsanity Resize and Compress

The easiest and most effective way I've found to automatically resize and compress images in WordPress is the plugin Imsanity. Here's how to use it:

  1. Back up all media (or entire site). BackupBuddy is my favorite backup plugin.
  2. Install and activate Imsanity.
  3. Settings > Imsanity. Leave the max width and height for Images uploaded within a Page/Post and Images uploaded directly to the Media Library as default (2048 × 2048), or change them to match your theme (for example, width of 1140).
  4. Set Images uploaded elsewhere (Theme headers, backgrounds, logos, etc) as default (2048 × 2048), or change them to match your theme. Or, set to 0 to disable resizing in these cases.
  5. Set JPG image quality to 80. Or, set it above 80, if you need images to look crisp on your site (such as a photography site or a retail site).
  6. Click Save Changes.

Now any images uploaded to the site will be automatically resized and compressed.

Bulk Resize Images

Imsanity can also resize and compress images that are already in your Media Library.

  1. Back up all media (or entire site). We use ManageWP for backups, but you can also use BackupBuddy.
  2. Settings > Imsanity. Scroll down to Bulk Resize Images and click Search Images.
  3. Select and deselect images to resize and compress.
  4. Click Resize Checked Images.

Need Help with Imsanity?

I didn't write Imsanity, and I don't provide support for it. You should read Imsanity's FAQ and post support requests in its support forum.

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12 comments on “Imsanity Plugin Automatically Resizes, Compresses Images in WordPress”

  1. Hi Chad- Great article. I'm a photographer and I have tons of images on my site. Even with a CDN & WP, I'm still loading slow. I stumbled across this article and have a question for you. Can I use Imsanity together with WP Or should I deactivate WP and then use Imsanity?


    1. Giganni, I'm pretty sure you can use Imsanity and WP together. I believe I tested that once. Hopefully Imsanity runs first to perform the bulk of the file size savings, then WP runs second to further optimize, but I don't know. You'll want to test.

  2. Thanks for a great post! If you use Imsanity and decide the compression doesn't look good can you go back to the way the images looked originally? Or do you have to upload new images?

    1. Andrew, Imsanity runs when the files are uploaded, so it affects the full-size originals uploaded to WordPress. If you run a batch resize on images already on the site, that too affects the full-size originals. So, if you don't like how the images looked after Imsanity does its work, you'll need to upload the images again.

    1. Thanks for the recommendation, ashim. We haven't used that plugin, and we're always wary of plugins with a low number of active installations (that plugin has 2,000+). Also, I noticed that you have promoted that plugin several places online. Are you part of the team behind the plugin?

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