The problem

I needed to answer this question: How many readers will be affected by the bigger size of the new site design?

Basically, I needed to know how many visitors are using a screen resolution higher or lower than the one I had in mind, which is 1280×800. A high proportion of visitors with a lower resolution than that would mean that I’d better reconsider downsizing the site to, say, a 1024 width, as it’ll impact negatively the usability of the site for them.

Fortunately, Google Analytics has a nice feature that can answer that question as long as you want to deal with regular expressions. And, fortunately again, I’ve done the hard work for you.

The solution

Time to access your Google Analytics account and:

1. In My Customizations (the sidebar at left, lower part), click on Advanced Segments.
2. Click on +Create a new custom segment (top right area)
3. Drag and drop Screen Resolution from the Systems submenu inside Dimensions (at left sidebar) to the dimension or metric grayed out box at right.
4. Change the Condition to Matches regular expression.
5. In Value insert this: (^12?[0-7]?[0-9]|^1?[0-1]?[0-9]?[0-9]|^[0-9]?[0-9]?[0-9])x
6. Type a name for this segment in the Name segment area ( I use: Lower than 1280)
7. Click on the Save Segment button.

Now, let’s see this in action:

1. For this example, let’s just check the Dashboard, so click on that link in the left sidebar.
2. In the top right area of the screen click on Advanced Segments.
3. That’ll show a popup with two lists. The one at left has the segments already built in Google Analytics. The one at right will show the one you just created (and any other custom segment of your own). Select it.
4. Click the Apply button.

There you have it. Just remember to uncheck All Visits if you only want the stats of that particular segment.

The regular expression

The important part in all the steps listed above is this:

(^12?[0-7]?[0-9]|^1?[0-1]?[0-9]?[0-9]|^[0-9]?[0-9]?[0-9])x

This regular expression is checking only the width of the user’s screen resolution, which is the aspect I was interested in, and should be just enough, in my opinion.

If you’re curious, this is what it does in detail. It checks if:

• ^12?[0-7]?[0-9]: The screen resolution width is somewhere between 1200 and 1279.
• ^1?[0-1]?[0-9]?[0-9]: Or between 1000 and 1199.
• ^[0-9]?[0-9]?[0-9]: Or between 000 and 999.

What about resolutions of 1280 and higher?

This part is way easier once the above segment has been created. Let’s say you want now to know the stats of those visitors with screen resolutions of 1280×800 and higher:

1. In the list of your Advanced Segments click on the Copy link in the entry you just created (that link is in the right part of the line)
2. Change the Condition to Does not match regular expression.
3. Type a name for the segment (I use: 1280 or higher)
4. Save the segment.

In my case, that will tell me how many visitors won’t have any problem with the new size of the site design I have in mind.

What about 1024×768?

If you have the same problem, but you’re wondering about screen resolutions of 1024×768, use this regular expression instead:

(^10?[0-2]?[0-3]|^10?[0-1]?[0-9]|^[0-9]?[0-9]?[0-9])x

Again, this only checks the width, not the height, but should be enough for most cases.

Conclusion and acknowledge

Now that I can easily see the amount of visitors with resolutions lower than 1280×800 I know that, taking the last month (November) as an example, they’re about 21,60% of the total visitors, which is a low percentage, as I expected. From those, only 16.24% are returning visitors, compared to the 65.83% of those with higher resolutions. Those percentages are quite similar in past months. It seems the new size won’t be a problem for most of the readers. That said, it’ll still be usable in resolutions as low as 1024×768, as the comic page and the navigation buttons will be centered and will fit perfectly in that resolution (you’ll have an annoying horizontal scrollbar at the bottom, though).

This trick is a personal adaptation of an article I found on Google, which focused on finding visitors who use mobile devices. That link points to the post where I found the information first, but it seems that this info has been copied over and over in other blogs, so I’m not sure if that’s the original source. In any case, thanks to whoever came up with this first.

That’s all. I hope someone finds all this of any use. Oh, and if you’re wondering, the new site design won’t be public until next year, I’m afraid.