Zen UV Checker is a Blender add-on for checking the state of a model's UVs using checker textures. It applies those textures through a node-based system, so checker maps can be added without ruining existing materials or creating new ones. A single click sets a checker texture, with Alt+T bound as the default shortcut.
The add-on ships with color and monochrome checker sets built to stay readable, offered in a range of texture sizes. A filter resolution system lets you sort existing textures by resolution and by square or rectangular format. You can also bring in your own checker texture or import an entire texture library, which the add-on handles through file access permission for the relevant folders.
Zen UV Checker is compatible with Blender 4.2 LTS and newer and is released under the GNU General Public License v3.0 or later. It can be added by dragging and dropping the file into Blender, or by downloading it and installing from disk.