In U.S. how do people pronounce often?
There's a website which I'm sure you will love:
It provides thousands and thousands of words pronounced by native speakers so you can hear different accents!
I hope it'll help :)
For most speakers, the "t" is silent, i.e. not pronounced. In some parts of the US, the word is prnounced as /ɔfn̩/, and in other parts as /ɑfn̩/.
You may find this link helpful: