Unreal Engine includes full access to the complete C++ source code, so you can study, customize, extend, and debug the entire Unreal Engine, and complete your project without obstruction.
Our source code repository on GitHub is continually updated as we develop features in our own mainline, so you don’t even have to wait for the next product release to get your hands on the very latest code.
Getting started with Unreal Engine source code access
Sign in to UnrealEngine.com with your verified Epic Games account. To open your account dashboard, hover over your username, and select Personal from the drop-down menu.
3. Connect GitHub
With your account dashboard open, select the Connections tab from the sidebar. Select the Accounts tab, and then select the Connect button below the GitHub icon.
4. Link the accounts
If you have not already signed the Unreal Engine End User License Agreement, you will need read through its terms and select the check box, then select Link Account. If you are signed out of your GitHub account, you will be directed to GitHub to sign in after clicking the Link Account button.
5. Authorize
To complete the OAuth App Authorization process, click the Authorize EpicGames button. You can learn more about this process in GitHub’s overview on Authorizing OAuth Apps.
6. Accept the email invitation
GitHub will send an email inviting you to join the @EpicGames organization on GitHub. You must select the Join @EpicGames button in this email within seven days to complete the GitHub and Epic Games account linking process.
That's it!
Upon completion, you will receive an email from Epic Games verifying that your GitHub and Epic Games accounts were successfully linked. If you don’t receive a confirmation email, or if your account is experiencing problems, get help from Customer Service. You are now ready to get started by going to our GitHub page (login required) to download the full source code.
Frequently asked questions
UE source code
What is GitHub?
GitHub is a widely trusted web-based hosting service for software development projects. The entire Unreal Engine source code is available on our GitHub page, ready for you to access!
Do I need source code via GitHub?
Most developers will have everything they need using the installed version of the engine, but if you want to modify the engine directly, or contribute your changes to the community, this is the right place for you.
What modifications can I make to the source code?
You can extend it, modify it, fork it, or integrate it with other software or libraries, with one exception: You can’t combine the Unreal Engine code with code covered by a “Copyleft” license agreement which would directly or indirectly require the Unreal Engine to be governed by terms other than the EULA.
Unacceptable Copyleft licenses include: Software licensed under the GNU General Public License (GPL), Lesser GPL (LGPL) (unless you are merely dynamically linking a shared library), or Creative Commons Attribution-ShareAlike License.
Acceptable Non-Copyleft licenses include: Software licensed under the BSD License, MIT License, Microsoft Public License, or Apache License.
Can I share Unreal Engine source code or tools with others?
You can share the source code or tools, along with any modifications you’ve made, with anyone who is an Unreal Engine licensee who is authorized to access the same version of the engine as yours, e.g. the 5.x.x version number of your installed build.
Can I copy and paste Unreal Engine code into my own project or engine?
If you use any Unreal Engine code in your product (even just a little), then your entire product is governed by the Unreal Engine EULA, and is subject to 5% royalties when your gross lifetime revenues from that product exceed $1 million USD.
Can I study and learn from Unreal Engine code, and then utilize that knowledge in writing my own game or competing engine?
Yes, as long as you don’t copy any of the code. Code is copyrighted, but knowledge is free!
Can I share code snippets online?
Unreal Engine licensees are permitted to post engine code snippets (up to 30 lines) in a public forum, but only for the purpose of discussing the content of the snippet.
Where can I go if I still have questions?
You can ask our community of experts if you have bugs, crashes, or other issues you need help with, and talk to other developers on the C++ Programming forum.
Can I join Epic Games' organization using a GitHub Enterprise managed user account?
No, managed user accounts cannot be invited to outside organizations. You will need to use a personal account to accept the email invitation and join the organization. You can find out more about the abilities and restrictions of managed user accounts here.