Checklist: A/B testing a builder landing page without tanking speed

Checklist: A/B testing a builder landing page without tanking speed

Most test scripts add render-blocking flicker — control for it.
— Duplicate the page as a variant template instead of injecting DOM changes client-side.
— If using a testing tool, load it async and hide-then-reveal to prevent flash of original content.
— Change ONE variable per test (headline OR hero OR CTA), not the whole page.
— Confirm both variants ship the same builder asset weight so speed isn't the hidden variable.
— Tag the variant in analytics by URL/parameter for clean attribution.

Pros:
— Server-side variants avoid flicker and speed penalties.
— Clean single-variable results.

Cons:
— Two templates to keep in sync.
— Builder duplication can drift over time.

Best for: conversion-focused pages where test-script bloat would skew results.