Search in
Sort by:

Question Status:

Search help

  • Simple searches use one or more words. Separate the words with spaces (cat dog) to search cat,dog or both. Separate the words with plus signs (cat +dog) to search for items that may contain cat but must contain dog.
  • You can further refine your search on the search results page, where you can search by keywords, author, topic. These can be combined with each other. Examples
    • cat dog --matches anything with cat,dog or both
    • cat +dog --searches for cat +dog where dog is a mandatory term
    • cat -dog -- searches for cat excluding any result containing dog
    • [cats] —will restrict your search to results with topic named "cats"
    • [cats] [dogs] —will restrict your search to results with both topics, "cats", and "dogs"

Building Unreal Engine from Source = huge file size

My question is, why does the Unreal4 file folder balloon from 9 to 24 gigs when I build the engine from source? In particular, there seems to be a lot of additional files in the Engine / Intermediate folder (8 gigs) in comparison to the release version downloaded from the launcher (172 MBs).

I am not an experienced coder, so my knowledge of Microsoft Visual Studio is limited at best.

I followed the instructions in Epic's documentation.


Downloaded version 4.8.3-release from Github and compiled a Development Editor build to Win64 with MVS.

Any clarification would be appreciated.

Product Version: UE 4.8
more ▼

asked Aug 06 '15 at 02:08 PM in Installation & Setup

avatar image

46 3 7 10

(comments are locked)
10|2000 characters needed characters left
Viewable by all users

1 answer: sort voted first

Hey zbuffer14-

The difference in file size is due to the source version including additional folders and files that are not required for the binary version. If you explore the Engine/Intermediate/Build/Win64/UE4Editor/Development folder for both directories you can see the difference in the files included in source versus binary.


Doug Wilson

more ▼

answered Aug 06 '15 at 03:06 PM

avatar image zbuffer14 Aug 06 '15 at 03:22 PM

Hi Doug.

Thanks for replying.

I'm just trying to build a slightly modified version of the Editor for my own use.

Is there a way to configure the build settings in MVS that will compile without these additional folders and files?

avatar image Tim C ♦♦ STAFF Aug 06 '15 at 05:48 PM

Hi zbuffer14,

Something you could try would be to delete the Engine/Intermediate folder after having built the Engine. The next time you open the Editor, it will take a little longer than usual as it rebuilds the parts of this folder that it needs. However, once that is done, you will have a much smaller folder and overall Engine size. Not quite the same size as the Binary Engine, but it will be significantly smaller than it was.

Keep in mind that if you do delete the Engine's Intermediate folder, you will not be able to make any changes to the Engine's source code and build the source code until you run GenerateProjectFiles.bat again. This will allow you to build the Engine again (which will require another full rebuild at this point), and then you can again remove the Intermediate folder to get the size back down a bit. In the case of your modified version of the Editor, you'll want to make any source code changes before you delete the folder since it will be more time consuming to make changes to the source code after you delete it.

When I tried this myself, the Engine/Intermediate folder went from approximately 8 GB (after building the Engine) to approximately 9 MB (after deleting the Engine/Intermediate folder and then starting the Editor).


avatar image zbuffer14 Aug 07 '15 at 12:38 PM

Thanks Tim.

avatar image zbuffer14 Aug 10 '15 at 10:28 PM

Hi again everybody,

Along these same lines. I've also downloaded and compiled the Unreal Tournament project and have noticed that this project file is a whopping 31 gigs -- that's after deleting the Engine / Intermediate folder.

Looking at the UnrealTournament content directory, its easy to see that approx 10 of those GB's are coming from there. The Engine / DerivedDataCache is of course quite large. Both of those are non-negotiable.

With the knowledge that I don't plan to modify code and re-compile again, what else can I possibly remove to get this project size down?

avatar image Tim C ♦♦ STAFF Aug 21 '15 at 07:42 PM

I am not sure if there is anything else that you can safely delete to reduce size on disk. Both the Intermediate and DerivedDataCache folders will be rebuilt when you open the project (and both should be at least a little smaller when this happens).

If you have no intention of working with code at all after initially creating the project, you may be able to delete the Source folder to save a little more space. However, I have never tested this, so I am not sure this is actually safe to do. In theory, once the project is built initially, all of the necessary code will be compiled into the project's .dll file, so the source code itself is no longer necessary. Just remember that if you do delete this folder, you won't be able to get it back. The other folders are all required, so don't delete any of those.

(comments are locked)
10|2000 characters needed characters left
Viewable by all users
Your answer
toggle preview:

Up to 5 attachments (including images) can be used with a maximum of 5.2 MB each and 5.2 MB total.

Follow this question

Once you sign in you will be able to subscribe for any updates here

Answers to this question