When you import images with URL Image Importer, each image is saved with a title and URL slug taken from its filename without the file extension — exactly the way WordPress names a file you upload by hand. For example, mountain-view.jpg becomes the title mountain-view. If your imported images already have clean, extension-free titles, that's the plugin working as intended.
It happens automatically — there's nothing to turn on
This is built-in behavior. Every image you bring in through the URL Import, CSV Import, and WordPress XML tabs automatically has its extension stripped from the title and slug. There is no checkbox or setting to switch it on or off, and it applies to every import.
Note: Earlier versions of the plugin had a Use filenames without extensions option on the import screen. That option has been removed because extension-free titles are now the standard behavior for every import. If you went looking for that checkbox and couldn't find it, this is why — you don't need it anymore.
Why It Works This Way
WordPress itself drops the extension when it builds the title and slug for a manually uploaded file, so sunset.jpg shows up in your Media Library as sunset. URL Image Importer follows the same convention so your imported images look and behave just like the ones you upload by hand — with tidy titles and clean, readable URL slugs that are friendlier for search and easier to find in your Media Library.
Still have a question about how your imported images are named? Submit a support request and a member of our team will get back to you within 24 hours.