Common language among internet users by country

I’m looking for some data for: “Common language among internet users by country”

I know it’s a bit of a mouthful, but consider this:

>> You’re making a website that is targeted at a specific country.
>> Within this country there are 3 different languages spoken
>> One of these 3 languages is the “official language” and is the most widely spoken
>> BUT when it comes to internet usage, the most commonly used language by people in that country who are connected to the internet is one of the other 2 languages spoken in that country

Does anyone know of anywhere on the web that gives information about the most widely used language by internet users from particular countries?

I have found information on the official language of countries and the most commonly used languages on the internet in general, but not the most commonly used language on the internet within a particular country.

Note: I’m just doing this out of interest as it would be good to know if I ever were to make a website targeted at a country that has more than one language spoken. I am not currently working on a site like this.