What are Mozilla compatible Agents in Google Analytics?

Question

When I create a pivot table showing the number of visits for each type of browsers and regions, here is what I obtain:

As you can see, regions such as Northen America the number of visits corresponding to Mozilla Compatible Agent represents a significant percentage (18% in that case).

While doing some research on the net, I came across this article on SEOmoz which talks about a bug related to Mozilla Compatible Agent.

Can someone with experience in GA tell me:

Q1: Can I trust figures under the 5. Mozilla Compatible Agent column?

Q2: How can I break down those figures to have more specific information on the type of browsers?

Breakdown for Mozilla Compatible Agent

Here are the totals per agent:

And here are the totals per device:

As you can see nothing obvious there as with some OS (e.g. Android) you can actually use different browsers. I just find it annoying that we can't get the exact breakdown per user agent string when clicking on Mozilla Compatible Agent (all you get is a line showing 5.0).

I guess I can at least conclude Mozilla Compatible Agents are mobile devices.

Solution

Do any of those numbers match iPhone visits elsewhere in analytics?

When an iPhone's app calls the built in browser it shows up as a Mozilla Compatible Agent rather than Safari. The user agent string looks like:

Mozilla/5.0+(iPhone;+U;+CPU+iPhone+OS+4_3_3+like+Mac+OS+X;+en-gb)+AppleWebKit/533.17.9+      (KHTML,+like+Gecko)+Mobile/8J2

This could be the source of the traffic.

Comments

[Su']

Regarding Q1, the problem there is very specific and may not even be affecting you. Did you actually do what the post suggests to find out first? The point is not "always distrust this user agent." (So, nobody can answer this question for you.) It's "if you see this happening, you might want to do some extra filtering."

[Kzqai]

Related google groups thread: productforums.google.com/forum/#!topic/analytics/68S1iUx3enA

[ASmith]

Unfortunately figures don't quite add up (see updated question).

[toomanyairmiles]

@user359650 do you have any log files to look at?