Have you ever had a site that you wanted to change the size of the thumbnail sizes for your posts?
In order to do this, you will need a WordPress plugin called “regenerate thumbnails“.
First go under your settings -> Media — Here you can select what thumbnail size you want. In this example we have choosen 1280 x 300. However once this is updated you are going to need a plugin that will help regenerate the images so that they crop to the new image size.
After you install the plugin in your WordPress Site – simply click activate. To resize your images, go under “tools” to regenerate thumbnails and simply activate the resize.
Once you have done this check your posts to see if your images are showing in the new size and you should be good to go!