Haaving a solid, well practiced, consistent thought process is one of several keys to real chess improvement. If you are moving without thinking you aren't playing chess.
What is better?

Yes, if you're just moving pieces around without knowing why, then you should slow down and try the online chess where you have time to think about what move to make. Even if you're just playing one day per move it will be a lot slower than playing live chess, but you'll have time to look at the board and think about what move to make.
I am a beginner chess player. Just started about a month ago and really enjoy it and have been playing games everyday. But I've been playing Online chess games where it takes a long time to finish a game. I play the live chess and it seems to fast and I cant really think thoroughly.
So I was wondering if its better to just play play play on live games even if I'm not thinking everything through or to play longer games where I can think about each and every move I could make?