- Not every company uses Google Analytics — and your A/B testing tool shouldn't force you to
- Some CRO tools are tightly coupled to GA4, while others offer independent statistics engines or alternative analytics integrations
- Varify.io supports GA4, Matomo, Piwik Pro, PostHog, and BigQuery — so you can evaluate experiments in whichever analytics tool you trust
- Privacy-first companies increasingly choose Matomo or Piwik Pro over GA4 — your A/B testing tool must support that choice
Google Analytics 4 is the default analytics tool for most websites. But it's not the only option — and for many companies, it's not the right one. Privacy regulations, data sovereignty requirements, or simply a preference for self-hosted analytics lead many organizations to Matomo, Piwik Pro, or PostHog. When those companies look for A/B testing tools, they discover an uncomfortable truth: most CRO platforms assume you use GA4.
This guide covers A/B testing options for teams that don't use Google Analytics — whether by choice or by policy. Varify.io is one of the few platforms that natively integrates with Matomo, Piwik Pro, and PostHog alongside GA4, giving you full flexibility in choosing your analytics stack. For a deeper analytics comparison, see our analytics integrations guide.
Why companies move away from Google Analytics
GDPR and data sovereignty
GA4 sends data to Google's servers — primarily in the US. Despite Standard Contractual Clauses, several European DPAs have questioned the legality of this transfer. Organizations in regulated industries (healthcare, finance, public sector) increasingly choose EU-hosted alternatives to avoid compliance risk entirely.
Data ownership concerns
With GA4, Google processes your visitor data for its own purposes (anonymized benchmarking, ad targeting signals). Self-hosted tools like Matomo give you complete ownership — no data sharing, no third-party access.
Sampling and data accuracy
GA4 applies sampling to high-traffic properties, which can distort experiment results. BigQuery export avoids this, but adds complexity and cost. Tools like Matomo and PostHog provide unsampled data by default.
A/B testing tools by analytics support
| Platform | Own stats engine | Matomo | Piwik Pro | PostHog | GA4 |
|---|---|---|---|---|---|
| Varify.io | Dashboard + analytics eval | ✅ Native | ✅ Native | ✅ Native | ✅ Native |
| VWO | Yes — full proprietary | ❌ | ❌ | ❌ | ✅ Basic |
| Optimizely | Yes — Stats Engine | ❌ | ❌ | ❌ | ✅ Basic |
| Convert | Yes — own tracking | ❌ | ❌ | ❌ | ✅ Native |
| Kameleoon | Yes — own analytics | ❌ | ❌ | ❌ | ✅ Basic |
Source: Claude Research, May 2026
Tools with proprietary statistics engines (VWO, Optimizely) can technically work without GA4 — but they create their own data silo. Varify is unique in supporting four alternative analytics backends natively.
How Varify works with Matomo, Piwik Pro, and PostHog
Varify's architecture separates experiment delivery from result evaluation. This means swapping the evaluation engine is straightforward:
- Varify + Matomo: Experiment events are tracked in Matomo. Results are evaluated directly in Varify's dashboard using Matomo data. Self-hosted Matomo means 100% data ownership.
- Varify + Piwik Pro: Native integration for organizations that chose Piwik Pro for its EU hosting and enterprise compliance features. Experiment data stays entirely within Piwik Pro's EU infrastructure.
- Varify + PostHog: Events appear in Varify's report within minutes. PostHog's product analytics adds rich user-level context to experiment results.
- Varify + BigQuery: For teams that want raw event-level data. No sampling, custom attribution, cross-platform analysis. Works independently of GA4.
In all cases, Varify itself doesn't set cookies and doesn't build its own visitor tracking layer. Your chosen analytics tool is the single source of truth.
Your analytics. Your experiments. Your choice.
Matomo, Piwik Pro, PostHog, BigQuery, or GA4 — Varify works with all of them.
Choosing the right analytics backend for A/B testing
Match your analytics choice to your priorities:
- Maximum privacy + self-hosting: Matomo (on your servers) + Varify. Zero third-party data access. Complete EU compliance. Free analytics + €149/mo testing.
- Enterprise EU compliance: Piwik Pro + Varify. Managed EU hosting, enterprise SLAs, dedicated support. Piwik Pro pricing + €249/mo Varify Pro.
- Product analytics focus: PostHog + Varify. Rich user-level data, feature flags in PostHog, A/B testing in Varify. PostHog pricing + €149/mo Varify.
- Data warehouse approach: BigQuery + Varify Pro. Raw event data, custom SQL analysis, unlimited historical queries. BigQuery usage costs + €249/mo Varify Pro.
- Google ecosystem: GA4 + Varify. The default for most companies. Free analytics + €149/mo testing.
For a full feature comparison across these options, see our CRO analytics integrations comparison.