This page explains how to unlock cheats in The Witcher 3 Wild Hunt. This can be done only on PC. The console versions don't have any cheats.
Important! Using the cheats listed below can block access to some game achievements. In some cases it can also break the balance of the game or make it impossible to finish some quests. It is recommended to make a backup of all current saves before using the cheats.
Unlocking the debug console where you can input the cheats
It's not easy to unlock the cheats in Witcher 3. The debug console where you can input cheats is unavailable by default. The only way to gain access to it is to install unofficial modification to the game called Debug Console Enabler. It can be downloaded from this website: http://www.nexusmods.com/witcher3/mods/28/
After downloading the mod you must unpack the .zip file and place its content into the directory of the game, to the \bin\x64 folder.
An example of a full path to install the mod: C:\The Witcher 3 Wild Hunt\bin\x64
Important! To work properly, this modification required Visual C++ Redistributable Packages for Visual Studio 2013 libraries. If, after installing the mode, the game doesn't want to start, it means you don't have these libraries. In such case, you can uninstall the mod and thus repair your game or download the libraries. The official website from which you can download the libraries is https://www.microsoft.com/en-us/download/details.aspx?id=40784
If you installed everything correctly and the game is working, from now on you can activate the debug console by pressing the ~ key or F2. After inputting the code press ENTER and close the debug window.