Left Sidebar vs Right Sidebar – Which One Performs Better?

Lots of people have lots of opinions on whether a left sidebar or a right sidebar is better for conversion.

There are a bunch of posts about it across the web but no one ever backs it up with data.

So I decided to run an experiment on this blog to see which performs better, a left sidebar or a right sidebar.

Personally I’m expecting the left sidebar to perform better than the right sidebar, but let’s see if I can back that opinion up with some data.

Left Sidebar Vs Right Sidebar – Fight!

I setup a split test on this blog, all I had to do was change one CSS value from right to left, and another CSS value from left to right – simple!

This is what the blog looked like-

I think the left sidebar looks pretty ugly to be honest, which is actually a good thing.

I don’t know why but for some reason ugly designs generally convert better – I suppose the same is true in the pub when you think about it ^^

Desperate nerd humour, I’m here all week!

Anyway – I setup the test on May 13th and let it run until May 24th exposing both setups to a total of 8,428 unique visitors.

Left Sidebar vs Right Sidebar Test Results

I decided to look at how the change in the left sidebar and right sidebar affected key metrics such as-

1. Bounce rate
2. Visit duration
3. Pages per visit
4. Conversion (email subscription/affiliate click/resource downloads)

I also decided to segment the data in 2 ways-

1. All Visitors – A look at all traffic both new & returning
2. New Visitors – Just new visitors – it is likely that returning visitors are already ‘trained’ to use the site. New visitors provide a ‘fresh’ look

You can click on any of the images below to get the full versions.

So first of all let’s take a look at how it affected all visitors.

All Visitors

Bounce rate, visit duration & pages per visit are up first-

And then conversion…

Let’s break it down in table format to make it a bit easier to read, digest & compare.

As you can see the differences really are marginal at best. The right sidebar does seem to perform slightly better, but its nothing to write home about.

Perhaps this is because my returning visitors are already ‘conditioned’ or ‘trained’ for the blog to look a certain way.

Let’s take a look at how new visitors react to sidebar alignment.

New Visitors

Bounce rate, visit duration & pages per visit are up first-

And then conversion…

Let’s break it down in table format to make it a bit easier to read, digest & compare.

As you can see there really isn’t much in it!

Although the right sidebar does perform slightly better as seen with the all traffic segment above.

Wrapping It Up

Based on my data I’m lead to believe that the sidebar position is mostly irrelevant.

Although the right sidebar did offer better pages/visit, visit duration and goal conversion there was barely anything in it.

Kinda feel cheated now after reading all of these exciting theories on which performs better =/

I’ll be honest I did expect the left sidebar to perform better due to the way we scan content and take it in.

It seems that as web users have become more savvy and particularly in this niche people are pre-trained to certain elements.

So as long as the sidebar is where people expect it be, at the side – it doesn’t matter if its left or right aligned!

You would be much better off worrying about the colour of your buttons or identifying & focusing converting traffic instead!