Server-side experiments
On this pageWhat it is
What it is
A server-side experiment decides which variant a visitor sees in your own code, before the page or screen is sent, instead of changing it in the browser afterwards. The tool supplies a software development kit (SDK) for your programming language, and your developers call it to ask which version to show. For example, you could test two pricing algorithms, a new checkout flow or a different search ranking, none of which a browser snippet can change. Convert Experiences, Optimizely and VWO are tools that list this feature.
Why it matters
Browser-based tests are fine for headlines, images and button colours. They struggle with anything that lives in your product logic, in a mobile app, or in an email sent from your systems. Server-side testing also avoids the brief flicker visitors sometimes see when a browser script swaps content. If your team only tests marketing pages and has no developer time, you will probably not need it. If product or engineering owns conversion, you will.
What to check
- Which programming languages and platforms have an official SDK, and is it maintained?
- Do results from server-side and browser tests appear in the same reports?
- How does the tool keep a visitor in the same variant across devices and sessions?
- Who on your team will write and maintain the integration code?
Tools with Server-side experiments
Runs A/B and multivariate tests on websites to track visitor behaviour and optimise conversion rates.
A/B testing and experimentation platform with tiered plans, a free trial and an official MCP server.
Experimentation and personalisation platform for testing websites and features, sold through a sales conversation.