Best Free A/B Testing Tools (Reddit Roundup)
"What are your favorite free A/B testing tools?" is a recurring thread on r/analytics. It usually comes up for the same reason: Google Optimize shut down in September 2023 with no direct replacement, and a lot of teams never replaced the habit of testing for free.
This page is published by Mida — an A/B testing platform, and one of the tools discussed below — so treat the Mida sections accordingly. We've tried to be specific about what each free tier actually includes, and what it quietly excludes, since that's usually where people get surprised.
Quick answer
The honest answer splits into two camps, not one winner.
Free forever, but you run it yourself
- GrowthBook is open source (Apache 2.0) and free with no usage ceiling — if you self-host it. You're responsible for infrastructure, uptime, and upgrades.
Free hosted tiers
- PostHog and Statsig both offer usable free tiers if your team already has engineers wiring up events and feature flags.
- Mida's free Sandbox plan covers up to 100,000 Monthly Tested Users with a visual editor and no credit card required — aimed at teams without a developer on hand.
GrowthBook: free forever, if you can self-host
GrowthBook is the name that comes up first in almost every one of these threads, and for good reason — it's genuinely open source, there's no license fee, and there's no usage cap if you run it on your own infrastructure.
The trade-off is that "free" here means free of licensing cost, not free of effort. You need somewhere to host it, someone comfortable maintaining it, and usually a data warehouse (BigQuery, Snowflake, or similar) if you want to use its warehouse-native analysis features.
GrowthBook also offers a hosted cloud plan with a visual editor, but the free, unlimited version is the self-hosted one. It's the right call for engineering-led teams that already run infrastructure and want full ownership of their experiment data.
PostHog and Statsig: free hosted tiers for engineering-led teams
Both PostHog and Statsig show up regularly in these threads as free, hosted alternatives that don't require you to run your own servers.
PostHog bundles experimentation with product analytics, session replay, and feature flags in one platform, and its free tier is usage-based across the whole product, not just experiments. Statsig leans on more advanced statistical methods (like sequential testing) and also has a generous free tier for smaller-volume use.
Both are built around SDKs and events rather than a visual, no-code editor. That's a natural fit if you're already tracking product events and have engineers who can instrument experiments in code — less so if you need someone non-technical to launch a test on a marketing page without a deploy.
Free A/B Testing Tool
Run your next A/B test the right way
Visual editor, 15 KB script, GA4-native — and free forever up to 100,000 monthly visitors. No developer required.
Mida: a free no-code option for teams without a developer
If you don't have an engineer on hand and want a visual editor instead of writing SDK calls, Mida's free Sandbox plan covers up to 100,000 Monthly Tested Users with no credit card required.
It includes the visual editor, a code editor for anyone who wants to write custom JS, and native GA4 integration so conversion events double as experiment goals. It's one of the more generous free tiers among visual-editor tools now that VWO has discontinued its free plan entirely.
The honest limits: it's a single-workspace Sandbox plan. Once you outgrow 100K MTU or need multiple team workspaces, the Growth plan starts at $299/month billed annually.
What "free" quietly excludes
A few things worth checking before you commit to any free tier, regardless of which tool:
- Whether the cap is on events, monthly tracked users, or seats.
- Whether A/A testing and multi-page funnels are gated behind a paid plan.
- For self-hosted options, the real cost of engineering time to deploy and maintain the tool versus paying for a hosted plan.
None of these are dealbreakers — they're just the kind of thing that gets left out of a two-sentence Reddit comment.
Free tools compared
Mida
Free Sandbox plan, 100,000 MTU, visual + code editor, native GA4 integration, no credit card.
Best for: teams without a developer who want a no-code visual editor.
GrowthBook
Open source, free forever if self-hosted, warehouse-native analysis.
Best for: engineering-led teams that want full control of their data and no usage cap.
PostHog
Hosted, usage-based free tier bundling experimentation with product analytics and feature flags.
Best for: product teams already tracking events who want experiments in the same tool.
Statsig
Hosted, generous free tier with advanced statistical methods like sequential testing.
Best for: engineering-led teams running high-velocity product experiments.
Prices and tier limits are approximate and change often — always confirm current details on each vendor's site. For a full comparison of 17 A/B testing platforms, see our Best A/B Testing Tools guide.
