Google Optimize shut down in September 2023. CROTool is the free replacement built on the same foundation — GTM for delivery, GA4 for measurement.
CROTool uses Google Tag Manager to deploy test variants and Google Analytics 4 to measure results — the same infrastructure Google Optimize used. No new scripts. No new analytics. Just the tools you already have.
Start free — no credit card required| Feature | CROTool | Google Optimize |
|---|---|---|
| A/B testing | Sunset | |
| AI variant builder | ||
| Deploy via Google Tag Manager | Native | |
| Track with Google Analytics 4 | Native | |
| Live preview on production URL | ||
| No extra scripts on site | ||
| Test planning & backlog | ||
| Team management | ||
| Visual editor | AI-generated code | |
| Multivariate testing | ||
| Free plan | Was free | |
| Available in 2026 |
Google Optimize was great for simple A/B tests but had limits: 5 concurrent experiments, no test backlog, no team collaboration, and no AI assistance.
CROTool removes those limits. Run unlimited tests on the free plan. Plan your testing roadmap with a built-in backlog. Generate variant code with AI. Collaborate with your team — assign tests, leave comments, track progress.
And because CROTool uses GTM and GA4 — the same stack Google Optimize used — migration is seamless. Your existing GTM container and GA4 property work out of the box.
Free plan. GTM + GA4. No new scripts on your site.
Start free — ship your first test in 5 minutes