How long compile time take?

For example, Unity engine, revise one source code and then click unity editor, compiling start, normally done within 8 sec (small, simple project) to 30 sec (big, complicated source).

Then how about unreal engine’s case? How long it take for compile after revise source code?

I haven’t experienced unreal yet, so curious.


How long is a string? It depends on your project and your hardware.

Besides what @Lambdarevolution said (which is a good point), what source code? The full engine? Plugin? Only your C++ project? What is a small simple project? What is big?

We cant give you any answers, you should try it.

If you are coming from Unity and havent used UE before - start with Blueprints. The compile time is often under a second.

Posting your question in place is enough: How long compile time take? - General Discussion - Unreal Engine Forums

Just give any example. Or just start with new project and make 1 c++ script, and right there Debug.Log(“Hello World”); (Unity C# example) and compile. Then how long time it will take?

of course its time… I said at title, just give me example then… or just assume like new project start and best hardware (i7 cpu, 64 ram, etc)

Then ill just say it’s fast enough that people still use unreal engine. I dont want to sound like a douchebag but whats the point of the question? Do you base your game engine on compile times? Unreal engine is free to download so i cant see whats stopping you from testing it yourself?

It completely depends on what the revision includes and hot reloading also adds an extra second and can be skipped if you just want to compile the code.

If you make changes to the header (add or remove functions etc.) then the UnrealHeaderTool (UHT) has to run.

It takes me about 9 seconds to run UHT and another 5 seconds to compile the code.

Hot reload takes < 1 second

So the worst case is 15 seconds and best case is 5 seconds.

Obviously the bigger the project the more time it takes.

I can test and tested already, but thats the starting point. I am also curious about latter situation of develop cycle. With many code lines and assets.

I have been an unreal engine developer for 5 years. I couldn’t find a solution to the compilation time issue. This changes increased my compiling time just 2-3 sec :

MinFilesUsingPrecompiledHeaderOverride = 1;
bFasterWithoutUnity = true;

this is very annoying. I am now using unity for casual style games. sometimes fast compiling and quick tests become more important than anything else of other engine capabilities.

Like the others have said, it really depends on your project size. But I have one advice. Use SSD. When I started using the engine, I didn’t have one. I swear to you that a started project take minutes to compile. with SSD, the longest I have so far was 40 seconds.

My compile time is currently near 20 minutes…

but for what? my whole engine compile time is about 45 minutes right now, but i’m only doing that whenever someone makes a base engine change, which is practically almost never, even in a big commercial product. (and even if they do, i have a script that runs every day and picks up the latest source and assets, compiles the source, and fills the DDC cache, so usually by the time i wake up every day to do work, i’ve got the latest everything and a fully filled cache, so i hardly ever have to wait for anything outside of my own builds)

My minimum build time is probably around 25 seconds, for single file changes with a usual live coding build time of around 50 seconds or so.