Optimizely vs Split

Quote on request

Free tier available

Enterprise annual contracts, commonly in the tens of thousands and up. Priced by traffic and modules.

Paid tiers are quote-based, priced by monthly tracked keys.

No free tier.

Free tier with limited monthly tracked keys.

Widely used

Optimizely · since 2010

Established

Harness · since 2015

• The most capable visual editor for non-technical experiment authoring.
• Deep personalisation and audience-targeting features.
• Established statistics with sequential testing, so peeking is handled correctly.

• Automatic metric impact on every flag catches regressions nobody thought to measure.
• Guardrail alerts stop a bad rollout before it reaches everyone.
• Strong data-platform integrations.

• Expensive, with a suite-oriented sales motion that pushes adjacent products.
• Client-side testing causes flicker and is increasingly blocked by browsers and blockers.
• Heavyweight for teams that only need a handful of experiments.

• Post-acquisition roadmap now sits inside Harness's broader platform strategy.
• Requires meaningful event instrumentation before the impact analysis is useful.
• Opaque enterprise pricing.

Large marketing organisations running continuous experimentation on high-traffic sites.

Teams that want every release measured, not just deliberate experiments.