What the maxium number of mods you can have,

[HoffBrian69]

I hear that Fallout 4 can handle more than 250 mods.

[monesq]

255 esp files and 200 - 500 "plug-ins".

 

These videos by Gamerpoet are entertaining and very informative. The attached link goes to a listing of his tutorials and musings.

 

https://www.youtube.com/c/gamerpoets/search?query=fallout%204

 

Good luck

[HeyYou]

The hard limit is 255 esp/esm files. esl files do not count toward that limit. Now, you can run as many mods as you want, so long as you don't exceed that hard limit. This is generally done by merging smaller mods into a single esp file.