Why the first compile takes so long?

Hello. I’m just wandering why my compile time takes so long (a few minutes) when I compile code for the first time (after opening ue4) and next times it’s like 10 seconds or so. Is it normal, or am I doing something wrong? I’d really like the first compile to go as fast as next ones.

Thats because the first time you compile everything. The next time you compile only what Changed. Thats how it is cant change that.

Can’t the engine use files compiled in previous session?

It does… thats why your second compile is faster than the first one. Be aware that Visual Studio itself has a small warmup time if you compile while its still warming up (Intelisense, analysing files, etc.) the compile takes a bit longer than usuall since it does it in parallel.

Alright, got it, thanks