Does FMA Brotherhood have fillers?

Fullmetal Alchemist (2003) has 33 confirmed filler episodes while there are only 2 fillers out of 64 episodes in Fullmetal Alchemist Brotherhood (2009). Since FMA stopped following the manga, there are tons of fillers that form a different story.

Which is better to watch FMA or fmab?

FMAB is a reboot, not a continuation, so it's not required to watch FMA first. However, because the two stories start off the same, FMAB goes through that first part a bit faster to get to the new story, which is actually the closer to the manga than FMA, which takes the story in a completely different direction.

Can you watch Fullmetal Alchemist without FMA?

You can definitely watch FMAB without watching FMA. Only thing is pacing of initial episodes of FMAB is quite fast as they are already covered in FMA. Yeah, why not. Fullmetal Alchemist is the anime version of the manga with few changes in story. And Fullmetal Alchemist: Brotherhood is the manga version with same story as the manga.

Do you need to watch FMA before Brotherhood?

This will allow you to enjoy both series to the fullest. If you watch FMA after Brotherhood, you aren't likely to enjoy it as much as if it was your first time since its more dated and less compact. Brotherhoods experience would become better by having watch FMA, as it builds the characters up more.