Optimizely compared to Unless

Optimizely vs Unless: how do they compare?

There are many conversion optimization techniques out there. A/B testing has been a longtime favorite, but, most recently, companies are starting to play with personalization. You can thank Netflix and Amazon for that. Although personalization is often associated with fancy algorithms, players like Optimizely and Unless have made it more accessible for non-technical people to leverage this CRO technique. Let’s see how these two services stack up against each other.


Optimizely is the poster child of the industry and, in many ways, has set several standards for CRO. With a wealth of experience built over 10 years, they have honed their product to service different professionals, including product managers and marketers, and have made several pivots along the way. They initially focused on A/B testing, but have expanded their product functionality to encompass data-driven personalization. Their product is feature-rich. It allows you to run multivariate tests, run different recommendation algorithms, and perform advanced audience targeting. They also offer integrations for other analytics and heatmap tools, helping you back-up your results with other data points.  

Optimizely customers can create experiments and personalized experiences across websites, mobile apps and connected devices. This is especially useful for large companies with lots of channels. The tool doesn’t come cheap. In fact, it went from being free to becoming a lot pricier than most CRO tools, but it competes well with Adobe Target and other enterprise-level testing solutions. Their wide feature offering is great, but makes it more complex to run if you’re new to the CRO game. You will likely have to work with a developer and a specialist to get a bang for your buck.

What makes Optimizely great?

It’s a solid product with a great set of features to run multiple CRO experiments.

What’s the biggest disadvantage of Optimizely?

It’s expensive and better suited for large enterprise companies.


Unless was founded in 2016, making it a new contender. It’s a personalization platform for websites that focuses on “contextualization.” The tool helps you tweak your word choices, images, and social proof (among other things) to appeal to different visitor segments. Like Optimizely, Unless is packed with features but it doesn’t come with A/B testing capabilities or heatmap integrations.  Using Unless, you can offer your visitors a unique user experience across multiple web pages or even subdomains – all the way from your landing page to your checkout, for example. Multiple personalized content snippets may fire on the same web page, allowing for very detailed personalizations. They recently released a library of “smart add-ons” which allow you to display a CTA bar and popups to your audiences. Their UI is pretty clean.

Unless’ implementation is similar to Optimizely’s. You need to add a script to your site. The difference is that Unless also offers you the possibility to submit your website URL and start personalizing from within the Unless dashboard before the script is installed. Once the system detects that the snippet is properly inserted in your website, it will automatically move your changes to the live view. In other words, you can get started with Unless faster if you wanted to.

What makes Unless great?  

Its super responsive customer service.

What’s the biggest disadvantage of Unless?

The solution is very specific and useful for personalization only. It’s not meant to be used for A/B testing and doesn’t come with the feature palette offered by Optimizely.

Which one should you use?

There’s no simple answer here. It depends on your business and what you’re looking to accomplish. If you’re looking for a quick takeaway, I’d say:

You should use Optimizely if:

    • You want to use an industry-leading tool that allows you to experiment with A/B tests and data-driven personalization.
    • You’re prepared to pay a considerable amount for a CRO solution.
  • You have technical resources and CRO specialists who will justify the investment and help you get the most out of the tool.

You should use Unless if:

    • You’re looking to become an expert at personalization and really squeeze the juice out of this CRO methodology.
    • You’re looking for a more affordable solution that doesn’t require technical skills.
  • You are looking for a technology vendor that will make GDPR compliance easy.

I hope this helps you choose the right tool. If you’re interested in learning more about these solutions and the features they offer, read our reviews for Optimizely and Unless.

Read more about these tools

Optimizely Review


Optimizely started off as an A/B testing tool and is seen as the leading experimentation platform.

Location: 631 Howard St, San Francisco, CAWebsite: https://www.optimizely.com/Phone: +1 800-252-9480

Unless Review


Unless is the new kid on the block, but making its mark on the industry already. It’s a

Location: Rokin 75Website: https://www.unless.comPhone: +31 207009345