E-Commerce “Compare” tools allow users to select products and view side-by-side sheets of their specifications.
Not all sites need a “Compare” tool, but it can be incredibly helpful to users in certain industries — when implemented well.
Indeed, during large-scale usability testing several of the “Compare” tools offered, even at large sites, proved more harmful to users’ experience compared to not having the feature at all, since users are still able to compare products on their own without a dedicated site feature.
This article will show the test findings from a large-scale usability study related to “Compare” tools. In particular:
- 3 checks to help decide whether providing a “Compare” tool is actually necessary for a particular site
- 3 UX requirements for “Compare” tools
3 Checks to Decide if It Makes Sense to Have a Comparison Tool
Comparison tools, while often helpful, aren’t always the right choice for particular sites or product verticals. Benchmarking reveals that it’s currently 38% of the 60 largest e-commerce sites that offer a “Compare” tool , almost unchanged from 40% back in 2015.
Indeed, many leading sites had a “Compare” tool that actually did more harm than good because it was implemented so poorly.
Therefore, before jumping right to deciding to implement a new “Compare” tool (or redesign an existing one), 3 crucial considerations must be made first:
- Whether there are existing product data integrity issues (52% of sites have issues)
- Whether product list items are high performing from an end user standpoint (46% of sites have issues)
- Whether it makes sense for the particular product verticals being considered
Is the data integrity good enough for comparison?
🛑 “It’s a bit annoying, because when it’s positioned like this then you would compare them, and then it seems a bit confusing when they don’t use the same unit of measure”, a user explained once he finally realized why the dimensions of the two cameras he was comparing at Tesco seemed so different. One of the products is defined in millimeters while the other is defined in centimeters.
First, proper product data is the foundation for any “Compare” tool. If there are sitewide issues with product data that is missing, unstructured, or unsynchronized then the “Compare” tool will simply not be usable for end users, as the tool is only as good as the data it’s highlighting. Data integrity is therefore an absolute necessity when it comes to “Compare” tools. Unfortunately, benchmarking of data integrity shows that it’s currently 52% of e-commerce sites that don’t post-process their vendors’ product data before its use on their own site.
If data integrity isn’t good, for example due to unprocessed vendor-provided product specifications, then don’t waste time implementing “Compare” tools. And if already implemented, consider removing the feature since it’s likely misleading users.
Is the baseline product list item UI good enough?
🛑 “Here I don’t really get any information besides the price and the name”, a user said when looking for a bag that would fit his laptop at Zappos. While a comparison feature would have helped, the real solution here is actually including category-specific attributes in the list item info (e.g., laptop size for all laptop sleeves), as that would greatly reduce the need for a “Compare” tool.
Second, “Compare” tools must not be substitutes for poorly performing product list items.
During testing, it was often the case that, when users said they wanted a comparison feature, they actually just wanted to compare a few list items across a single key product attribute that should have been part of the list item information in the first place. For example, users who wanted to know what size laptops would fit within a particular laptop bag when considering a product list of laptop bags.
Rather than relying on a “Compare” tool, having the right category-specific list item attributes will often solve the issues. This is especially true for less spec-driven industries and product verticals, where a handful of key product attributes are often sufficient for users to compare products directly from within the product listing page.
Does a “Compare” tool make sense for the product vertical?
✅ Many spec-driven product verticals — such as these amplifiers at Musician’s Friend — benefit from having high-performing “Compare” tools, as they allow “power users” an efficient way to compare product specifications across several different products.
Third, it should be considered which product verticals need “Compare” tools — and which can “get by” with proper list item info.
Testing revealed that spec-driven verticals — for example, appliances and electronics — are best-suited for “Compare” tools, as users will want to compare a wide range of specs (and not just one or two key specifications).
For these types of products, “Compare” tools can enable users to consider their available options in a very structured manner (which appeals strongly to a certain subset of users).
This is especially true when a core subset of your users are “experts” or “professionals”. These users are often able to make better use of “Compare” tools, as they are typically better able to interpret all of the nitty-gritty product details and thus methodically compare products, because they better understand the often minor or highly technical differences.
3 UX Requirements for “Compare” Tools
Now, assuming that the above three conditions have been met — product data is well implemented sitewide; list items contain the necessary product info, including crucial category-specific attributes; and it makes sense for a particular product vertical — then it is often a good idea to provide users with a “Compare” tool.
However, the “Compare” tool itself must perform well to be beneficial — in particular, when users first encounter it, which is typically in the product list.
Testing revealed 3 requirements to ensure the “Compare” tool performs well in the product list:
- On desktop, show the “Compare” link only on hover
- Provide explanatory tooltip text
- Provide easy and prominent access to the comparison interface
On desktop, show the “Compare” link only on hover
✅ This mockup illustrates only displaying the “Compare” checkbox for the list item the user is currently hovering. The “Compare” checkbox is absent in the list items until a user hovers a particular list item. None of the sites in the benchmark database only show the “Compare” option for the list item a user is currently hovering (all sites instead display the option permanently).
Showing the “Compare” link only for the list item the user is currently hovering reduces clutter in the product list for the users who don’t want to use it (which is typically the majority of users), while still keeping the option directly available in each list item, reminding the user that the “Compare” tool is an option.
When an element changes on the page — in this case, a “Compare” checkbox appearing in a list item — it typically becomes more noticeable to users, who are also then more likely to actually read any associated text.
Thus, displaying the “Compare” checkbox only on mouse hover, rather than permanently, increases the likelihood that users will both see and understand the purpose of the “Compare” checkbox, as they’re more likely to read the “Compare” label.
Provide explanatory tooltip text
✅ During testing, some users mistook “Compare” links and buttons in list items as being for another feature, such as an off-site price-comparison feature or a product-customization feature, or simply assumed that clicking the “Compare” link would take them directly to the product page. Providing explanatory tooltip text (as seen here), along with using a checkbox design, can help better identify the “Compare” link.
By displaying a tooltip, additional context can be provided for the otherwise very short “Compare” label. Combined with only displaying the checkbox on list item hover, this greatly reduces the chance of the checkbox being mistaken for another feature.
Provide easy and prominent access to the comparison interface
While Walgreens permanently displays the “Compare” link, and doesn’t provide explanatory tooltip text, the “Compare” feature is very difficult to miss once the “Compare” checkbox is clicked, as it expands from the bottom of the interface. Users are also provided with similar products to compare if they only select one — a helpful way of guiding users to other relevant products they may be interested in.
It should be immediately obvious to users how to access the “Comparison Page” after clicking a “Compare” link for a product list item. For example, a “Compare Selected Products” button should appear in the list item immediately after clicking the “Compare” link. This way, the user is given an easy way to access the comparison view, which is accessible right where they clicked the “Compare” checkbox.
Furthermore, after selecting the first product, a “Comparison” header may be attached to the top or bottom of the user’s screen, showing thumbnails of the selected products along with a “Compare Selected Products” button. This gives users a way to track their selected items as they scroll through the product list, as well as a permanently visible way of accessing the “Comparison Page”.
Implementing these three details will lower the risk of “Compare” tools being misunderstood by users, while still keeping the tool visible and accessible from each list item (when they are hovered).
Ensure Comparison Tools Help — Rather Than Hinder
If “Compare” tools are easy to find and navigate when in the product list, they can lead to an interface that’s designed specifically to facilitate product comparison. Listing specs for similar products, especially spec-heavy products, side-by-side helps users thoroughly consider the options available to them.
In general, “Compare” tools aren’t a requirement for users attempting to decide among a few different products.
Testing revealed that there’s a danger in simply assuming that a “Compare” tool is necessary to have — poor-performing “Compare” tools often left users more indecisive about the product they were interested in purchasing, instead of guiding them to their product of choice.
But high-performing “Compare” tools can be a boon to users ready to dig deep into product specs — which is often the case for users making expensive or complicated purchases online.
To ensure “Compare” tools are easy to find and navigate, they must:
- Have “Compare” checkboxes or buttons that appear only when hovering a list item
- Provide explanatory tooltip text
- Provide easy and prominent access to the “Compare” tool once an item has been selected for comparison
A high-performing “Compare” tool will help guide users to a suitable product — making it more likely they’ll wind up finding a product that they end up purchasing.
PS. If you’re looking for inspiration for a compare tool, “Compare” tool designs page has 43 examples of the largest e-commerce sites.