If you are migration from another theme that supports WordPress featured images functionality, you will notice that all your images that were uploaded after activating the theme are looking just as expected but all your old images still have their original dimension.
Trying to adjust the size manually from the Settings will not correct the problem. All your image thumbnails must be regenerated in newly defined dimensions that your current theme supports.
Fortunately, this process is a lot easier with a plugin called Regenerate Thumbnails that will automate the whole process:
- Install the Regenerate Thumbnails plugin and activate it.
- After activating the plugin, navigate to Tools.
- Click Regen. Thumbnails.
- Now click Regenerate All Thumbnails and wait until all thumbnails are completely regenerated.
- That’s it! now check you website again.