How to Create Pixelate (Pixelize, Blur) Effects in GIMP
If you got sensitive information to blur out, GIMP is a great tool for pixelate (pixelize) either the whole image or just certain zone of your selection. In this tutorial we'll be covering how to use blur filters on GIMP to create pixelate effects.
Pixelate
Click Pixelize in Blur category of Filters:

Adjust the Block width and Block height to the blurriness of your liking:

Pixelate Certain Zone
Use Rectangle Select Tool (shortcut: R
) to select the desired zone:

Create the pixelate effect by repeating the previous steps:
