Testing and CRO
Optimizely vs VWO
VWO is the practical choice for most companies: testing plus heatmaps, recordings and surveys in one place, with a free starter tier. Optimizely is for organisations running experimentation as a discipline, with server-side tests and feature flags across product teams.
- No affiliate links
- Public pricing only
- Updated by hand
Both do split testing properly with sound statistics. The gap is scope: Optimizely has become a broader digital experience platform with feature experimentation for engineering teams, while VWO stayed focused on conversion optimisation for marketers.
Price follows. Optimizely is quote-based and enterprise-shaped; VWO publishes pricing and has a free tier.
Side by side
Optimizely and VWO in short.
Optimizely
Enterprise experimentation and digital experience platform, including server-side testing and feature flags.
- Free
- No self-serve free tier.
- Paid from
- Quote only, typically enterprise contracts
Good at
- Server-side and feature-flag experimentation engineers will trust
- Handles very high traffic and complex experiment programmes
- Statistics engine designed for continuous monitoring
Weak at
- Expensive and sales-led
- Requires dedicated experimentation staff to be worth it
VWO
Conversion optimisation platform: A/B testing, heatmaps, recordings, surveys and personalisation.
- Free
- Free starter plan with limited monthly tracked users.
- Paid from
- Paid plans from a few hundred dollars a month, by traffic
Good at
- Testing, behaviour analytics and surveys under one subscription
- Visual editor marketers can use without a developer
- Published pricing and a free tier to start
Weak at
- Less capable for server-side and product experimentation
- Costs scale with tracked users
The differences
Where they actually diverge.
Pick one
Which one fits you.
Choose Optimizely if
- Engineering runs experiments behind feature flags
- You test continuously across several products
- Statistical rigour is scrutinised internally
Choose VWO if
- A marketer will build and read the tests
- You want qualitative and quantitative data together
- You need published pricing to get approval
When neither is the answer
Under about 10,000 monthly visitors, A/B testing rarely reaches significance in a useful timeframe. Use recordings and interviews to find problems, ship the fix, and measure the before-and-after.
Questions
Common questions.
How long should a test run?
At least two full business cycles — usually two weeks — even if significance arrives sooner, so weekday and weekend behaviour are both represented. Stopping early on a promising result is the most common CRO mistake.
Is there a cheaper way to test?
PostHog includes experiments on its free tier, and Google Optimize's 2023 shutdown pushed many small teams there. It's a reasonable starting point if you're already tracking events.
Prices are list prices published by each vendor and change often — check the linked pricing pages before you buy. We take no affiliate commission and nobody pays to appear here.
gtm.help
Skip the tool research. Get the plan first.
Paste your website and gtm.help reads it, then writes a ranked growth plan for your business — with the tools each task needs, what they cost, and what to do first. Free to start.