You likely don't need a plugin for this — paint.net can do this natively:
Or simply: Layers → Layer Properties → Opacity slider to 255 paint net alpha to 255 plugin download
Before downloading any plugin, it is crucial to understand what “Alpha” means. In digital imaging, every pixel has four channels: You likely don't need a plugin for this — paint
When an image has partial transparency (Alpha values between 1 and 254), it can cause issues: Or simply: Layers → Layer Properties → Opacity
The “Alpha to 255” plugin does exactly one simple thing: It scans every pixel in your image or selection and forces the Alpha channel to 255 (full opacity) while leaving the RGB colors untouched.
Note: Some Paint.NET versions place it under Effects → Color or Effects → Rendering, depending on the plugin’s metadata. If you don’t see “Tools,” check those menus.
A: Yes, almost all classic plugins work. If you get a “bad image format” error, use BoltBait’s Plugin Pack version 6.1 or later, which includes an updated Alpha to 255.