Optimizely vs Split
Feature checklists rarely decide anything. What decides it is the pricing metric, who has to write the tests, and which limitation you can live with.
Entry price
Quote on request
Quote onlyFree tier available
Free tierWhat drives the bill
The metric that actually scales your invoice.
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.
Free tier
No free tier.
Free tier with limited monthly tracked keys.
Open source
Self-hostable
No-code authoring
Languages
Platforms
Fits teams
Adoption
Widely used
Optimizely · since 2010
Established
Harness · since 2015
Strengths
- 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.
Limitations
- 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.
Best for
Large marketing organisations running continuous experimentation on high-traffic sites.
Teams that want every release measured, not just deliberate experiments.
All of these integrate with: Segment, Snowflake, Slack.
Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.