Thanks for getting in touch @zackuzman, and great question. Depending on your configurations with Performance Lab plugin active (Settings > Media > Generate JPEG files in addition to WebP), there can be both a WebP and JPEG version of the images you have uploaded.
As it sounds like you only have WebP versions of your images generated, after uninstalling the plugin the WebP images will remain, so you can keep these as normal if you wish, meaning they’ll remain visible in your pages and posts if already inserted. Going forward your images when uploaded will be the standard format which you upload in, without being impacted by the Performance Lab plugin (no longer active). In other words, no action is required or best practices applicable, if deactivating or uninstalling the Performance Lab plugin.
If you specifically wish to remove the WebP images, you will need to do so via your WordPress media manager. You can then upload your own JPEG images if you wish. You will need to check the pages and posts which contained the WebP images previously, and replace these with the JPEG version.
You can also use third party image plugins that convert image formats in bulk, while also replacing the formats should the images be already inserted into pages or posts.
Basically restore the site to its previous state.
The plugin at present only created WebP version of images uploaded after activating the plugin. This means that in order to restore your site to it’s previous state, you just need to remove the WebP images as suggested above – the images uploaded after you activating the plugin. You can then upload the images once more, in JPEG format.
Let me know if you have any questions with the above.
