Free A/B Testing Tools (2026): 5 Free Google Optimize Alternatives
The free A/B testing tools that are left after Google Optimize: PostHog, GrowthBook, Statsig, Mida and Humblytics, with each free plan's limits read from the vendor's page.
The short answer: Google Optimize closed in 2023, and no one tool replaced it for free. Five tools still let you run A/B tests at no cost. PostHog and Statsig have large free tiers but are built for developers who test in code. GrowthBook is open source with a free cloud plan for up to 3 users. Mida has a free Sandbox plan with a visual editor, 100,000 monthly tracked users and 3 live tests. Humblytics has a no-code visual editor, scores tests on sales in Stripe, and gives the first 25,000 data points free with no card; your AI agent can set it up. Every limit below was read on the vendor's page on 3 November 2026.
One thing no tool can give you for free is enough visitors. A test needs enough conversions to show a real difference, and that usually takes weeks. Before you pick a tool, check how long your test will take with our test duration calculator.
At a glance
| Tool | Free plan | Limits | No-code visual editor | Built for |
|---|---|---|---|---|
| PostHog | Free tier, no card | 1M feature flag requests a month (experiments bill with flags) | Not the main way to test | Developers |
| GrowthBook | Free Starter (cloud), free self-hosted | Up to 3 users, unlimited experiments | AI visual editor on paid plans only | Developers and data teams |
| Statsig | Free Developer plan | 2M events, 50K session replays a month, unlimited seats | Not the main way to test | Product and engineering teams |
| Mida | Free Sandbox | 100,000 monthly tracked users, 3 live tests per project | Yes | Marketers |
| Humblytics | Free start, no card | First 25,000 data points, 1 site | Yes | Marketers and AI agents |
1. PostHog
PostHog's free tier needs no card and includes 1M feature flag requests a month; experiments are billed with feature flags. It also gives 1M analytics events and 5K session recordings (posthog.com/pricing, 3 November 2026). Tests usually run in code, so you will want a developer.
Pick it if an engineer runs your tests and you want analytics and replay in the same tool.
2. GrowthBook
Open source. The free Starter plan on GrowthBook Cloud covers up to 3 users with unlimited feature flags and experiments; the AI visual editor is on paid plans, which start at $40 per seat a month. Self-hosting the open-source version is free (growthbook.io/pricing, 3 November 2026). It works best when your data already sits in a warehouse.
Pick it if you have a data team and want full control.
3. Statsig
Statsig's free Developer plan includes 2M events and 50,000 session replays a month with unlimited seats; the first paid plan is $150 a month (statsig.com/pricing, 3 November 2026). Like PostHog, it is built for product teams testing in code.
Pick it if you test features inside an app, not landing pages.
4. Mida
Mida is the closest free swap for marketers who used Google Optimize. Its free Sandbox plan has a no-code website visual editor, 100,000 monthly tracked users and 3 live tests per project. The first paid plan is $224 a month billed yearly (mida.so/pricing, 3 November 2026).
Pick it if you want a visual editor and only need a few tests at a time.
5. Humblytics
Humblytics has a no-code visual editor for changing copy, buttons, images and layout on your live page, and split URL tests. Each variant can be scored on a conversion or on the revenue it brought in through Stripe or Foxy. The same script gives you analytics, heatmaps, funnels and Meta and Google Ads spend.
Your AI agent can set it up: paste one prompt into Claude Code, Codex or Cursor, and it reads app.humblytics.com/agent.md, signs you up, installs the script and can suggest a test. A test goes live to real visitors as soon as it is created, so the agent confirms the change, the page and the goal with you first. Tests stop after a set number of days (30 by default), not when a result looks significant.
The first 25,000 data points and 1 site are free, with no card. After that the Agents plan is $39 once for 100,000 data points; team plans are $79 and $279 a month.
Limits: the free start is not a forever plan; when the data points run out, tracking pauses. No server-side tests or feature flags. No session replay.
Pick it if you test landing pages and want to know which version makes more money.
How to choose
- Developers testing features in code: PostHog, Statsig or GrowthBook.
- A marketer who wants a visual editor and a few tests: Mida's Sandbox.
- A marketer who wants tests scored in sales, with heatmaps and ad tracking in the same tool, set up by an AI agent: Humblytics.
FAQ
What replaced Google Optimize?
Nothing official. Google closed Optimize in September 2023. The free options above are the closest replacements.
Is there a completely free A/B testing tool?
Self-hosted GrowthBook is free with no usage cap, but you run the servers. Hosted free plans all have limits: users, tests, events or data points.
Which free A/B testing tool has a visual editor?
Mida's free Sandbox and Humblytics' free start both include a no-code visual editor. GrowthBook's AI visual editor is on paid plans.
How long should an A/B test run?
Until it has enough conversions to detect the change you care about, and at least two weeks to cover weekly patterns. Use the sample size calculator to work it out.