Counting users for a browser or an operating system, or just about anything at scale, is very difficult. LinuxPlanet has an article posted by Steven J. Vaughan-Nichols titled How Many Linux Users Are There (Really)? He spends the bulk of the article basically saying that none of the measures we have are useful and he concludes by pitching a project designed to try to count Linux users with a new tool.
I was a bit disappointed because with a headline like that, I expected some answers :-)
Not one to sit around disappointed, I decided to try to come up with a number myself.
This is all fuzzy math, with a lot of assumptions and lots of rounding, but I think I can do a little better than Steven offered for an answer.
I don't think anyone would disagree that the overwhelming majority of PCs (laptops and desktops being used by human beings) in use today are connected to the Web with Web browsers. I don't know what that number is but let's say it's 90% to 95%. It may even be more, but let's go low for the sake of this investigation.
I'm going to just assert that Firefox represents somewhere between 75% and 90% of Linux browsers in use today. It's probably higher, but that range shouldn't be controversial.
update: for those saying we don't see Linux distro-packaged Firefox update checks, yes, you're right. We do see plug-in blocklist pings and that's what I was measuring. Sorry for the confusion.
OK. So that works out to Firefox Linux browsers representing somewhere between 65% and 85% of all Linux PCs. Let's hold that for a second.
Now, looking at our Firefox numbers, we can positively identify Linux at at least 2% of total Firefox browsers based on update checks. There are some "unidentifiables" in our measuring right now, so I'm going to be generous and allow that most of those unknowns could be Linux. That would put Linux somewhere between 2% and 5% of active Firefox browsers. (Just to let you compare, Mac is ~7% and Windows is the rest.)
Estimating Firefox's total number of active browsers isn't an exact science since we don't track individual machines, but we've worked out over time that it's approximately a 3x multiplier against our "active daily users" count. Right now that count is about 85 million, so we estimate our installed base at ~250 million.
So now we do the math :)
If we look at the "worst case" there are as few as 5.5 million Linux PCs out there.
If we look at the "best case" there are as many as 16.5 million Linux PCs.
That's a pretty big range, but it's certainly a start.
Next, let's look at it from the usage direction. NetApplications, TheCounter.com, and Google Zeitgeist (before they stopped publishing the number) all measure web browser traffic to get OS stats and all put Linux at ~1% of their web browser usage.
That's usage, not users/installed base, so people who use the web more, are going to be somewhat over-represented. It's probably a safe bet that Linux users are at the higher end of the usage spectrum so doing the straight math on usage % against total users would give Linux a bit of extra credit. That's OK as long as we keep in mind that this method of counting will paint a somewhat rosier picture for Linux users
The total number of people on the internet is estimated (by the folks that get paid to estimate these things) somewhere between 1 billion and 1.6 billion. We're talking about people here and not browsers. With multiple people sharing a single computer more common than individuals using more than one computer, again the number will come out high.
So we do the math again :)
Working back from usage data and total internet population, we get between 10 million and 16 million Linux users.
There are probably other directions we could approach this, but I don't know what they are and looking at this from a couple of angles, we can already see that there's some agreement about the high end. It's unlikely that there are more than about 16 million Linux PCs in use today.
At the low end, there's less agreement, but I think it's reasonable to just mash those two numbers together and say that there are probably no fewer than about 8 million Linux PCs.
That's still a pretty big range and while I'm usually an optimist, I think if someone asked me how many Linux users there were, I'd just split the different between the high and low and say there were about 12 million of them. That feels about right to me.
I want to restate that this is all fuzzy math, with a lot of assumptions and lots of rounding and mixing up of users and usage and installed base and whatnot. Still, I think it's was a useful exercise and I think it's probably not too far from reality.
What do you think? Does 12M-16M feel right to you? Got a better way to estimate that you'd be willing to share here? Got better data on any of the points I used in my estimate? Think this is all nonsense and not worth thinking about? Please share with us in the comments.