How to Fix Wrong-Sized Images in WordPress

One of the things that often confuses people new to WordPress (and web-tech in general) is that you can rely on WordPress to keep track of your images. Set some as featured, add them in your posts, all of that stuff. If you don’t know that, it’s so cool to discover. But then a second thing happens: you use this power, but then you change themes (or something else) and all your images are wrong. They’re not the right size, or at least not the size you set in your theme.

This will look lots of different ways, depending on the specifics. Any of the symptoms for which this is the cure are:

  • You’re seeing full-size images on your WordPress site with code you think should be requesting a specific size
  • You’re seeing too-small or fuzzy images in your site in places where you’d expect the right size
  • You notice that new images look great, but older images seem a little “off”

If any of these is the case, what you need to do is regenerate the images on your site. What WordPress does with images, as a favor to you, is create all the sizes you’ve registered on your site when you upload a new image. But changing themes (and a few other less common scenarios) will often mean you need image sizes that WordPress didn’t create for your when your first images were created. That’s where Regenerate Thumbnails comes in.

Regenerate Thumbnails is a great free plugin that makes it easy to fix up your WordPress image library and get everything working. Like its name suggest, it doesn’t harm your library, rather it just re-creates all the non-source image sizes WordPress keeps for you as if you uploaded images to match your site settings right now. This is why you’ll get the right sizes if you need if you’ve switched themes.

Here’s a video explaining its use:

And if you prefer, here’s the text explanation of using Regenerate Thumbnails…

Weird Image Size Issues in WordPress? Do This!

  1. Install and activate the “Regenerate Thumbnails” plugin. To do that, go to “Plugins > Add New” in your left sidebar of the administration area, and search in the box for “Regenerate Thumbnails”. Click the “Install” button on that result, which should then become the “Activate” button. Click “Activate”.
  2. Go to “Tools > Regen. Thumbnails”. This is a little different than most plugins, so you do need to know where to look.
  3. On the page click the (only) button: “Regenerate All Thumbnails”. This will start the plugin running. Leave this tab open while it runs. How long its takes varies *a lot* with image library size. It’ll typically be between 1 second and 15 minutes.
  4. When that screen is complete, you’re done. All your images should look as expected!

Regenerate Thumbnails offers a nice little report of the errors it finds. Usually it doesn’t have any, and you’ll be golden. Onto new problems! 🙂


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kuhnbnSFM
February 25, 2020 9:20 am

My WP uses its own resized images, but the variants that are too small! I think this is an issue with the media uploading, as old images work fine. It is just the new ones!

idealnewstv
May 23, 2019 11:36 pm

thank you but nothing has changed for either??????

Jo
March 27, 2019 5:57 am

Nothing has changed for me either 🙁

Tom Clark
March 20, 2019 1:21 am

Nope, nothing changed after following all of the above.

Ryan
August 31, 2018 12:45 pm

Thanks for info! Images still didn’t return to the correct size, unfortunately.