Quick Tip: Build an editor Utility in UE4 (Updated August 2020)

Skip to 57:00 for the actual start of the tutorial.

This stream covers how to build Editor Utility tools in Unreal. These tools can handle meta tasks, like editing assets (Actors) in a scene or the content browser. For example, you could make a tool that renames assets that don’t follow a naming convention, or a tool that fixes actor placements in a level.
These tools seamlessly integrate into the right-click menu of the Unreal Editor. All of this can be done with Blueprints.

Note this feature has existed in some form in Unreal since version 4.20.

[Updated, because the original post lead to a dead link and was generally outdated.]