10 Ways to Optimize Filters In ecommerce

Ecommerce filters are a navigation tool crucial to any eCommerce platform as they help customers find products fast. Filters allow shoppers to narrow down the range of items in your store, ensuring the smoothest user experience possible, whether the intent is low or high. 

The Use of Ecommerce Filters

Effective filters reduce user decision fatigue by narrowing down the often overwhelming product selection on online stores. Applying filters to highlight relevant attributes narrows down the options and reduces friction on the path to purchase. Each filter reflects each customer’s unique needs and preferences, increasing customer engagement and driving sales. Especially if your store has thousands of SKU’s, optimized product filters are necessary.

Common filter suggestions include: brand, price, color, user rating, material, size, theme, popularity. Filters can also be thematic depending on seasons or promotions. For each different product category, relevant filters should be suggested. These filters can be based on product descriptions or sourced from google analytics to relate to what customers are most commonly searching for.

Best Practices

1. Horizontal or Vertical?

Filters are most commonly found on the left hand side of the page as a horizontal toolbar. The vertical option has the advantage of being a familiar user experience; it’s where customers expect to find them. There is the option to add a large number of filter options as it offers the opportunity for space.

A horizontal toolbar is more visible, as it attracts shopper attention and adds user convenience. However this option has limited space and it should be taken care that menu’s don’t automatically disappear when the cursor isn’t hovering over them.

There is, of course, the option to employ a hybrid vertical and horizontal model. Many websites use a combination of both. The crucial thing is ensuring a seamless user experience. 

2. Use A Broad Range

A ‘one size fits all’ approach does not work with filters. Some customers may be buying with intent, or some just open to browse. In order to help all cases a range of filters should be used, either product specific or thematic. For example, when dealing with car parts specific terms could be used as filters to identify the models. But when selling gifts, themes such as ‘anniversary’, ‘birthday’ and ‘graduation’ could be used which are much broader terms. These enhance value and promote storytelling, whereas the functional filters can be employed for more high-intent buyers.

3. Keep Language Simple

Your filters should be written in the same language your customers use to search for products. Using the terms that shoppers use makes it easier for them to find what they are looking for. Rather than trying to be creative or show specialist expertise when designing the language for the filters, merchants should be thinking about what creates the least confusing customer journey. For the same reason, avoid using industry jargon as many customers will not be experts in the product range. Remember that filters are not a branding exercise; their functionality and simplicity is far more important.

4. Optimize for Mobile

Mobile phones continue to account for more of the eCommerce market, meaning that mobile-commerce should remain at the forefront of merchants’ minds. Having a mobile first mentality should apply to all areas of your website, including ecommerce filters. Filters should be optimized for mobile phone use. Ensure that the options don’t cover all of the screen, and that the filters still remain as accessible and practical on the mobile device as they do on a bigger screen.

5. Multiple Values Allowed

Sometimes shoppers will want to apply more than one filter, and they should always be allowed. Customers may want to select several options at a time; either if they know precisely what they are looking for, or they are unsure and want to narrow down the possible options. Allowing more than one filter to be applied means that the AOV can be increased, and all possible products that could meet their demands are displayed.

6. Keep It Clear

Filters are there to make the buying journey easier, so make sure this stays the case. The moment filters start to become confusing or distracting, they are defeating their purpose. It should be clear to the user when filters have been applied, so they know which filtered products they are viewing. Interactive filtering is also useful, meaning that as soon as a filter is selected the page changes. Without the user having to take an extra step to see their preferred selection, the journey to buying is smoother. Batch filtering would only be preferable if your site has issues with speed.

7. Don’t Forget To Merchandise

It’s important not to overlook merchandising strategy and rules when it comes to filters. Setting promoted filters will help shoppers narrow down results and aid the merchant’s business goals. By placing certain filters at the top of the list, attention will be grabbed and shoppers will be directed according to strategic characteristics. 

For the same reason, irrelevant filters should be buried low at the bottom of the options. This means they will only be ticked if customers actively search for them. This helps influence which sales your business makes.

Promoting filters should also be considered in terms of user ease. For example, if someone is looking for shoes, jewelry filters should be buried as they are not relevant and will not aid the current considered purchase. Ordering filters alphabetically isn’t the best strategy either; ordering them according to customer’s frequent searches is a better strategy.

8. Personalization Still Applies

Don’t forget to use personalization when it comes to filters. Returning customers can have their ecommerce filters saved for the next time they visit the site. This shows them that the business cares about them. Using the shoppers’ browsing history to suggest relevant filters to them can help to boost conversions and positive shopping experience.

9. Consider The Numbers

When deciding how many filter options to display, the Goldilocks principle should be applied. Don’t overwhelm the shopper with too many filters, but don’t disrupt their decision process with too few. Rather than listing every color possible, for example, just display the most valuable ones. If there are more filters that you think are helpful, you can add a ‘View More’ option for customers looking to search deeper.

It’s also a good idea to display the product quantity next to the ecommerce filters. This avoids over-filtering and people can then know whether or not it’s helpful to click on that filter or not. If there are very few products in that category, they might want to select more than one. 

10. Never Show 0 Results

A golden rule in eCommerce is never to display the dreaded ‘0 Results’ page. A basic UX non-negotiable is to relocate a page with no results to related products, or relevant items based on the user behavior. Any filters that would lead to 0 results or to out of stock items should be buried, as this only infringes the user experience. Dynamic filtering can mean that only products that are in stock are shown, and these can be very useful.


In order to make sure your ecommerce filters remain effective; keep on testing. Running A/B tests on filters should not be overlooked. If certain categories aren’t getting clicked; examine why. With regular testing, filters are an amazing and certain way to improve the user experience and boost conversions.