Optimizely vs ABTestly. An honest comparison.
Optimizely does not publish pricing. Figures below are third party estimates, marked as such. Checked on 7 July 2026.
Yes, we are ABTestly, so read this knowing who wrote it. Every ABTestly claim is checkable against our own live site, every Optimizely price figure is attributed to third parties (Optimizely publishes none), and there is a real section below on where Optimizely beats us. Because it does, in several places.
Head to head
| Optimizely | ABTestly | |
|---|---|---|
| Pricing model | Quote only. No public pricing. Plans page routes to contact sales | Published tiers, Free to Enterprise, on one page |
| Entry paid price | Not published. Third party estimates put Web Experimentation in the tens of thousands of dollars a year (commonly cited $25k to $40k) | Pro: $249 / mo, or $199 / mo billed annually (100,000 MTU). Starter: $99 / mo (25,000 MTU) |
| Enterprise | Third party estimates: $200k plus a year at scale | Custom |
| Free option | None documented publicly | Permanent free plan: 1 experiment, 3,000 MTU |
| Editor | Visual editor plus code | Monaco code editor. JSON configs. No visual editor |
| Test types | A/B, multivariate, multi arm, personalization, feature experimentation, full stack, server side, feature flags | A/B testing with multiple variants and split URL tests. No multivariate, full stack or feature flag experimentation |
| Statistics | Optimizely Stats Engine with sequential testing (their published methodology) | Three engines available (Frequentist on every plan; Sequential and Bayesian on Pro): frequentist, sequential, bayesian. Applied to conversion and revenue |
| Sample ratio guard | Automatic sample ratio mismatch detection, documented | Yes. Chi square check flagged on the results panel |
| Public methodology | Yes, Optimizely publishes their Stats Engine paper | Fully documented on docs.abtestly.com |
| Delivery | Global CDN | Cloudflare edge, 300 cities, config served without an origin round trip |
| Snippet | Anti flicker supported. Size not published | ~27 KB gzipped runtime, loader under 1.5 KB, anti flicker opt in |
| Integrations | Large enterprise catalog, program management tooling | Writes an exposure event with the experiment and variant to your data layer; your GA4 or GTM setup forwards it |
| Overage handling | Contract based, negotiated at renewal | No automatic overage charges. Notified at 80% and 100% |
| Support | Dedicated CSM, phone, SLA (contract dependent) | Email. Priority email on Pro and up |
| Compliance | SOC 2 Type 2, ISO 27001, GDPR / HIPAA / EU data option | GDPR conscious with consent deferred mode documented. No published certifications yet |
| Refunds | Contract based, no public money back guarantee | 30 day money back guarantee on your first paid month. Data preserved on downgrade |
Optimizely publishes no list price for Web Experimentation. The dollar ranges above are third party market estimates, not official figures. If Optimizely publishes a price after this page is verified, update it against optimizely.com/pricing.
Where each one wins
Where Optimizely genuinely wins
- Enterprise experimentation scale. Full stack, server side, feature flags, multi arm, and program management tooling built for teams running hundreds of experiments across products.
- Stats Engine. A published, peer reviewed sequential testing methodology that has been in production for years.
- Feature flags and rollouts. A first class product surface, not just for tests.
- Enterprise vendor. Established brand, procurement paperwork ready, dedicated CSMs, SLAs.
- Integrations and program management. Fits into an enterprise data and workflow stack.
Where ABTestly is better
- Pricing you can read. Four tiers on one page. Pro $249 / mo for 100,000 MTU. Optimizely is quote only.
- Free plan. Permanent free tier with real features. Optimizely has none documented publicly.
- Code first workflow. Variants are authored as explicit JavaScript and CSS in Monaco, with linting and change history, making the code straightforward to review and copy into your own version control.
- Edge delivery. Config served from Cloudflare's edge in 300 cities.
- Snippet size stated up front. ~27 KB gzipped, loader under 1.5 KB.
- Three statistics engines available. Frequentist on every plan. Sequential and Bayesian on Pro. No add on to unlock either one.
- No automatic overage charges. Going over your MTU never generates a surprise bill.
- 30 day money back guarantee on your first paid month. Try a paid plan, walk away if it does not fit.
Which should you pick?
Pick Optimizely if you are an enterprise buying a platform, need full stack experimentation and feature flags, have procurement asking for MSAs and SLAs, and can budget for a quote only contract.
Pick ABTestly if your team writes code, your stack reports into GA4, and you want a published price and a free tier to validate before you commit. See our pricing, or read the full Optimizely pricing breakdown to understand how much Optimizely costs.
Genuinely unsure? Start on the ABTestly free plan and run a real test in an afternoon. The Optimizely alternative page is the shorter read if you are earlier in the search.
Quick answers
How much does Optimizely cost versus ABTestly?
Optimizely is quote only and does not publish pricing. Third party estimates (not Optimizely's official figures) put Web Experimentation roughly in the tens of thousands of dollars a year, commonly cited around $25k to $40k, and $200k plus at enterprise scale. ABTestly publishes its pricing: Pro is $249 / mo, or $199 / mo billed annually, for 100,000 monthly tracked users, with a permanent free plan to start.
What does Optimizely have that ABTestly does not?
Full stack and server side experimentation, feature flags, a mature Stats Engine with sequential testing, multivariate testing, a visual editor, a large integration ecosystem, and enterprise program management tooling.
What does ABTestly have that Optimizely does not?
Published pricing and a permanent free plan instead of a sales process, no automatic overage charges, three statistics engines (Frequentist on every plan; Sequential and Bayesian on Pro), a code first workflow that lives in version control, a data layer exposure event your existing GA4 or GTM setup can forward to GA4, edge delivery from 300 cities with a snippet around 27 KB gzipped, and a 30 day money back guarantee on your first paid month.
Which should a small team choose?
If you need enterprise experimentation at scale, Optimizely is built for it. If your team writes code, reports into GA4, and wants transparent statistics at a published price, ABTestly fits, and you can validate it free before deciding.
Optimizely does not publish pricing. Third party estimates cited. Checked on 7 July 2026. ABTestly is not affiliated with Optimizely.