TL;DR
For headless CMS: Use ExperimentHQ for visual A/B tests on any frontend, or Statsig/LaunchDarkly for server-side testing. Headless architecture means you can choose any testing tool—the CMS doesn't limit you. Focus on your frontend framework (Next.js, Nuxt, Gatsby) when choosing.
Tool Comparison
| Tool | Approach | Headless Support | Verdict |
|---|---|---|---|
| ExperimentHQ | Client-side | Best Visual | |
| Statsig | Server-side SDK | Best Server-Side | |
| LaunchDarkly | Server-side SDK | Best Feature Flags | |
| GrowthBook | Both | Best Open Source |
Popular Headless CMS Options
| CMS | Frontend | Notes |
|---|---|---|
| Contentful | Any | Use client-side or server-side testing |
| Sanity | Any | Integrates with Next.js, Gatsby, etc. |
| Strapi | Any | Self-hosted, works with any frontend |
| Prismic | Any | Built-in A/B testing for content |
Testing Approaches
Client-Side (Visual)
- + Easy setup
- + Visual editor
- + No code changes
- - Potential flicker
Server-Side (SDK)
- + Zero flicker
- + Feature flags
- - Requires code
- - More complex setup
Our Recommendation
For headless sites: Start with ExperimentHQ for visual tests. Add server-side testing later if you need zero flicker.