Hypothesis-driven CRO vs full UX redesign: comparison, budget split guidance, and when each wins.
Redesigns ship many changes at once with no isolation of which change drove (or hurt) conversion. CRO ships isolated tests with measured per-change attribution. Redesigns make sense for major brand or platform changes; CRO makes sense for ongoing optimization.
Hypothesis-driven CRO wins when conversion-rate is the binding constraint on revenue — that is, when the site has reasonable traffic but low conversion. Symptom: rising traffic, flat revenue. Diagnosis: conversion bottleneck. Treatment: CRO investment.
full UX redesign wins when traffic is the binding constraint — that is, when conversion is reasonable but traffic is low. Symptom: high conversion rate, low absolute revenue. Diagnosis: traffic bottleneck. Treatment: full UX redesign investment.
For most clients running both: depend on which constraint is currently binding. Typical starting blend: 60-70% full UX redesign investment for traffic + 30-40% CRO for conversion when traffic is the bottleneck; reverse when conversion is. Re-evaluate quarterly as the binding constraint shifts.
Almost always — they compound. The question is the budget split, not the choice.
Start where the binding constraint is. If traffic is low, fix traffic first. If conversion is low, fix conversion first.
Look at the funnel: high traffic + low conversion = CRO bottleneck. Low traffic + high conversion = traffic bottleneck. Both low = both bottlenecks (start with whichever has faster ROI in your context).