Building UE4 from Source

A quick guide for how to compile the Unreal Engine 4 source code on Windows so you can run it portably without installing Epic Games Launcher.

Requirements

• You need to have access to the EpicGames/UnrealEngine repository on Github, don't have access? Follow this procedure: https://www.unrealengine.com/en-US/ue4-on-github
• A version of Visual Studio (2015 and newer should work, however some of the newer releases might need 2017 or 2019)
• A git client (unless you prefer the terminal)

Step by step

• Clone the repository and choose the version you want to run by selecting the appropriate branch
• Open your favorite terminal and navigate to the folder you cloned it to
• Type in setup and wait for it to finish
• Type in GenerateProjectFiles and wait for it to finish, when done you can close down the terminal
• Navigate to PathToUnrealEngineRepository\Engine\Extras\UnrealVS and install the UnrealVS extension appropriate for your installation of Visual Studio.
• Once installed you can go back to the root of the repository and open up the project in Visual Studio with the UE4.sln solution file
• Right click in the empty UI area next to the Start compile button and click UnrealVS in the dropdown.

• Click the cogwheel that's to the right of the newly added UnrealVS toolbar

• A new window opens with various views with all the projects, configurations and platform targets. Inside the Projects view go ahead and select UE4, ShaderCompileWorker and UnrealBuildTool by control-clicking them so you individually select those. Then select Development Editor  in the Config view and lastly select Win64 as the platform.

• Grab a beverage while it builds, it's gonna take a while...
• Once it's done you can get to the Development Editor by launching UE4.exe found inside the folder PathToUnrealEngineRepository\Binaries\Win64

Now you can enjoy developing with Unreal Engine straight from the source code, which in my case became useful as I sometimes use my work laptop for this and don't want to install anything on there that isn't work-related. So now I can relax on the couch and tinker with my projects in UE4 that's running from my external drive on the laptop 😄

If you wanna dig in more you can check out the documentation here: https://docs.unrealengine.com/en-US/Programming/Development/CompilingProjects/index.html