I believe that the more common one is "fæk".
According to Wikipedia:
Since the acronym FAQ originated in textual media, its pronunciation varies; "fack," "fax," "facts," and "F.A.Q." are commonly heard.
Wikipedia's sources are the Jargon file and FAQs about FAQs .
english.stackexchange.com/users/127/Mehper C. Palavuzlar
I have only ever heard it pronounced 'Eff Ay Que'.
However it does seem to be one of those phrases that will never have a 'proper' pronunciation.
english.stackexchange.com/users/523/Dhaust
In a general sense, initialisms and acronyms are most properly pronounced as the letters, e.g. "Eye Arr Ess" or "Arr Pee Jee" rather than "Erse" or "R'pug."
Pronouncing the letters individually rather than coming up with a pronunciation for something that is not an actual word avoids misunderstandings.
That being said, especially in contexts where the given acronym or initialism will be used often (FAQ in a web context; various military acronyms)
there will often be an accepted pronunciation that the community recognizes for use within the community.
english.stackexchange.com/users/1552/munin
The only reasonably objective way I can think of to gauge the relative popularity of the pronunciations "fack" and "f-a-q" is by consulting a Google Ngram Viewer chart for "a FAQ" versus "an FAQ.
" Here's the chart I got matching "a FAQ" (red line) against "an FAQ" (blue line) for the years 1980 through 2008 in English-language publications of all sorts: Though historically "a FAQ" has been more common, the results for the two options are so close for the last few years included in the chart that their relative popularity in 2014 is anyone's guess.
The results for American English publications are much the same as the overall results: But the results for British English publications are somewhat friendlier to "an FAQ" and yet at the same time seemingly more volatile: On the strength of these charts, both pronunciations of FAQ appear to be thoroughly mainstream.
As a precautionary measure, you might ask around to see whether a consensus exists in your workplace favoring one pronunciation or the other, since such a local consensus might amount to a house style on pronunciation.
But if no such consensus exists, I think that you should feel free to use whichever pronunciation you prefer.
english.stackexchange.com/users/36232/Sven Yargs
In order to avoid misunderstandings I think FAQ should be pronounced as an initialism (where you keep each letter separated: Eff-Ay-Kyu) rather than as an acronym (where the letters are pronounced as a word: fack).
english.stackexchange.com/users/24155/sticksandstones
Definitely articulate each letter individually...
Don't say "fack" or when I was younger, in my mind FAQ = "
f
*** u" which made me really confused.
Never heard anyone say anything besides F A Q anyways.
english.stackexchange.com/users/343946/Helen C.
I hear FAQ(s) pronounced like a word in "FACK(s)", while I go letter by letter. In usage, what is more common?  (Similar to SQL vs Sequel)
What is the commonly accepted pronunciation of FAQ?
english.stackexchange.com
<colloquialisms><acronyms><pronunciation>
english.stackexchange.com/questions/4165
english.stackexchange.com/users/None/
Since the acronym 'FAQ' originated in textual media, it is likely to have a range of ways of pronouncing it. However, the most popular way is probably to articulate each letter individually. Since the acronym FAQ originated in textual media, its pronunciation  varies; "fack," "fax," "facts," and "F.A.Q." are commonly heard.   The majority of people probably pronounce it as 'Eff Ay Que'.      V
It is generally thought to be pronouced as 'Eff Ay Que'. However,  "fack," "fax," "facts," and "F.A.Q." are commonly heard. Since FAQ primarily appears in print media, it is likely to have a range of ways of pronouncing it. However, the most popular was is probably to spell out the individual letters.
Since the acronym FAQ originated in textual media, its pronunciation  varies; "fack," "fax," "facts," and "F.A.Q." are commonly heard.    The majority of people probably pronounce it as 'Eff Ay Que'.      
It appears that the most common pronunciation is to spell out the letters individually. Since FAQ primarily appears in print media, it is likely to have a range of different ways of pronouncing it.