Why use Rig UI Pro? Because it will supercharge your rig UI and its functionalities not only with simple bone collection visibility controls but with bookmarks, special actions, custom properties, armature extras, and specific panels for different popular armatures like AutoRig Pro and Rigify.

Bone Collections
Bone Collections Documentation

Manage buttons for each bone collection. Pin the collections you want to display.

Traditional bone collections UI or Pro version for extended functionality:

Isolate the collection’s visibility. (LMB)
Select all bones in the collection. (shift LMB)
Toggle bone collection visibility. (alt LMB)
Configure Bone Collection. (ctrl LMB)
Add new bone collection with currently selected bones (ctrl shift LMB)

Highlight the bone collection containing the active bone.

Bone Collection Move Mode

When active, you can move elements to other bone collections from an intuitive UI directly on the bone collections buttons UI.
Different options to display where your bone is and where you can move it, including displaying unpinned groups (always, never, while moving).
Fade out other collections (toggle)
Fade unpinned groups (toggle)

Visibility Bookmarks
Visibility Bookmarks Documentation

Store the current view state of the bone collections and recall it with one click (swap between FK / IK clicks with ease or activate and deactivate secondary controls).
Check tooltips for hotkeys to use them like a pro.

Custom properties
Custom Properties Documentation

Pin any exiting custom property of any bone into a panel.
Add new custom properties to the PROPERTIES bone. The PROPERTIES bone and collection are created automatically if they do not exist.
Manage all the custom properties from the UI, including editing them, and select the bones that hold them.
You can choose to display their name inside or outside of the property.

Grouping
Grouping Documentation

Group Bone Collections and Custom Properties.
Each group has a style to choose from a dropdown so you can have the look and feel you want in your rig UI.
Group Styles
No style
Label
Box
Box with label
Collapsible box label
Collapsible label

Pop-Up Panel
Pop-Up Panel Documentation

Add your Rig UI to a configurable hotkey to access it from anywhere in the 3d viewport.

General Options
General Options Documentation

Change the Sidebar for the Rig UI.
Export basic UI for the rig (WIP feature).
Rigify my Rig UI
Change the order of all the modules
Armature Extras
Armature Extras Documentation

Several UI tools to work with the armature from the UI panel

Normal pose / Rest pose toggle, and Pose Library
Object / Pose / Edit modes
Bone “display as”
In front, bone names, bone axis, custom shapes, bone colors.