Every A/B test has to decide which visitor sees which version. That decision can happen in the browser or on the server, and the choice shapes your page speed, your accuracy and what you are able to test at all.
We choose the right method for each test through our A/B Testing service, matching the approach to your stack and goals.
Client-side testing runs in the browser. The page loads, then a script swaps in the variant. It is quick to set up with a visual editor, which is why most teams start here, but the swap can be seen.
Server-side testing decides the variant before the page is sent, so the visitor receives the chosen version fully formed. It needs developer involvement but avoids the flicker and opens up tests the browser cannot reach.
Neither method is better in every case. The right choice depends on what you are testing and who can build it.
| Factor | Client-side | Server-side |
|---|---|---|
| Setup effort | Low, visual editor | Higher, needs developers |
| Flicker risk | Possible | None |
| What you can test | Front-end changes | Front and back end |
Use client-side testing for fast front-end experiments like headlines and layouts. Move to server-side when flicker is hurting results or when the test touches pricing, functionality or anything the browser cannot safely change.
If shoppers report seeing the page change as it loads, that flicker is skewing your results. It is the clearest sign to move that test server-side.
Most testing programmes begin within one to two weeks once tracking and goals are confirmed. Contact our Brisbane team on (07) 3184 9197 for a current schedule.
TPR Media operates from Level 34, 1 Eagle Street, Brisbane City QLD 4000, serving clients across Brisbane and Australia-wide.
TPR Media chooses between client-side and server-side A/B testing by what is being tested and who can build it, using server-side delivery to remove flicker and reach pricing and logic changes.