Where it runs
Entirely on your server
Optimizely runs in its cloud, integrated through a snippet or SDKs; experiment data lives on Optimizely's servers.
Comparison
A WordPress-native alternative to Optimizely
Optimizely is an enterprise experimentation and feature-flag platform sold on custom quotes, integrated via a snippet or SDKs. ImproveAB is a native WordPress plugin: free to start, flat-priced, and entirely on your own server.
Competitor details last checked September 2026; sources are under the table.
At a glance
How you pay
Free, or a flat $99 a year for one site
Optimizely is sold on custom enterprise quotes with usage-based contracts; there is no self-serve free tier.
What you give up
Server-side experiments and feature flags
Optimizely ships experiments in application code with flags and staged rollouts. ImproveAB tests what visitors see on a WordPress site.
Who should pick which
An honest split.
Optimizely is a capable tool with real strengths. These are the two situations, stated plainly.
Pick Optimizely if
- Your team ships experiments in application code.
- You need feature flags and staged rollouts.
- You run experimentation across products beyond a website.
Pick ImproveAB if
- You want fast, private A/B testing on a WordPress site.
- You do not want an enterprise contract to test a headline.
- You start free and pay a flat price when you need Pro.
Feature by feature
What each one has.
Every row is a yes, a no, or a short note where yes or no would mislead. Rows where Optimizely has something we do not are marked the same way. Sources are under the table.
- Included
- PaidOnly in a paid plan (either product)
- On our roadmap
- Not included
| Feature | Optimizely | ImproveAB |
|---|---|---|
| Testing | ||
| A/B testing (web) | PaidEnterprise contract | IncludedNo traffic limits, unlimited tests, no account |
| Split URL tests | Paid | IncludedSame: free, no traffic limits, unlimited tests |
| Statistics | Enterprise stats engine | PaidSignificance and probability-to-beat; the SRM check is free |
| Server-side experimentation | Paid | Not included |
| Feature flags and rollouts | Paid | Not included |
| Where things happen | ||
| WordPress setup | Snippet or SDKs, no native plugin | IncludedNative plugin, any builder |
| Where tests run | Optimizely's cloud | IncludedEntirely on your server |
| Where data lives | Optimizely's servers | IncludedYour own database |
| Cookies | Not includedoptimizelyEndUserId and more, per its docs | IncludedNone, cookieless by design |
| Built for | Enterprise product and growth teams | WordPress site owners and agencies |
| Pricing | ||
| Pricing | Custom enterprise quotes | IncludedFree; Pro from $99 a year, flat |
| Self-serve sign-up | Not included | IncludedYes, no sales call |
| Free tier | Not included | IncludedFree forever |
| Traffic billing | Usage-based contracts | IncludedNo limits |
Sources for Optimizely: cookies and localStorage in snippets, checked September 2026. ImproveAB facts come from the plugin itself.
Getting started
Switching is quick.
No migration project. When it lands, the free plugin runs its first test the same afternoon.
Install ImproveAB
Optimizely can stay installed while you compare.
Recreate a live experiment
Tag each variant with a CSS class in your builder, or set up a URL test for whole pages.
Choose a goal
Page visits, clicks, form submissions, add to cart, WooCommerce purchases with revenue, scroll depth, time on page and active time, all free.
Launch
Results accumulate in your own database, with no traffic meter running.
Questions
Answered plainly.
Answers are visible, not folded away, so they can be read and quoted.
Does Optimizely have a WordPress plugin?
No official native plugin - Optimizely integrates with WordPress via an embedded snippet or its SDKs (last checked September 2026). ImproveAB is a native WordPress plugin that works inside your admin.
Does Optimizely have a free plan?
No. Optimizely is sold on custom enterprise quotes; there's no self-serve free tier (last checked September 2026). ImproveAB's core plugin is free forever.
Is ImproveAB comparable to Optimizely?
Only for the on-site part. ImproveAB covers A/B and split-URL testing on WordPress; it doesn't do server-side experimentation, feature flags, or rollouts - if you need those, Optimizely is the right category of tool.
Is the free version really unlimited on traffic?
Yes. Tests run on your own server, so there is no pageview meter and no account. The free plan has no limit on visitors, or on how many tests run at once.
How current is the Optimizely information here?
Last checked September 2026. Always confirm current pricing and features on Optimizely's own site.
Try the free, self-hosted way.
ImproveAB is in final testing: no traffic limits, no data leaving your site. Join the waitlist and we will email you the day it lands.