Inventory editors

Inventory editors allow you to add or remove items from your local player inventory, and in many cases, edit other character data.

Terrasavr
A full inventory and character editor in a mobile app.

Terraria InvEdit
A full Windows-based inventory and character editor, designed to be compatible with Steam.

TerrariViewer
This software has not been updated since october 2013, so you might skip it if you want full compatibility with your games