European Alternative to Optimizely

Smart Experimentation for European Enterprises

AB Tasty is a Paris-based experimentation and personalization platform trusted by brands like Sephora, Decathlon, and L'Occitane. It enables product and marketing teams to run A/B tests, feature experiments, and AI-powered personalization, all with data hosted in the EU.

Built for Product and Marketing Teams

AB Tasty bridges the gap between product development and marketing optimization:

• A/B and multivariate testing: Test designs, copy, layouts, and features with statistical rigor
• Feature flagging. Roll out features progressively with full control over who sees what
• AI-powered recommendations. Personalize product and content recommendations in real time
• Server-side and client-side testing. Flexible experimentation across your full stack

Enterprise-Grade Compliance

As a French company, AB Tasty processes all data within the EU by default. The platform is designed for organizations that need to move fast without compromising on data sovereignty.

Enterprise Experimentation and Personalization from France

Kameleoon is a French experimentation platform offering A/B testing, feature management, and AI-driven personalization. It serves enterprise brands that need sophisticated testing capabilities with full GDPR compliance and EU data hosting.

AI-Powered Optimization

Kameleoon combines traditional testing with artificial intelligence:

• A/B and multivariate testing: Test variations across web, mobile, and server-side
• Feature management. Progressive rollouts with audience targeting and kill switches
• AI personalization. Machine learning predicts the best experience for each visitor
• Full-stack experimentation: Client-side, server-side, and hybrid testing modes
• Analytics integration. Connect with your existing analytics and CDP tools

Built for Regulated Industries

Kameleoon is used by European banks, insurers, and healthcare companies that require the highest data protection standards. All data processing happens within the EU.

Privacy-First A/B Testing from the Netherlands

Convert Experiences is a Dutch A/B testing and personalization platform that puts privacy at the center of experimentation. Founded in 2009 in Amsterdam, it is one of the few testing tools that stores no personal data and uses no third-party cookies by design.

Experimentation Without Privacy Trade-offs

Convert provides the testing capabilities teams need without the data baggage:

• A/B and multivariate testing: Test page variations with a visual editor or code-based changes
• Split URL testing: Direct traffic between different page versions for larger redesigns
• Personalization: Show targeted content based on visitor segments, geography, device, or behavior
• Advanced targeting: Target experiments by URL, cookie, JavaScript condition, or data layer values
• Statistical engine: SmartStats uses Bayesian and frequentist methods to call winners accurately
• Flicker-free deployment: Async snippet loading prevents the visual flash common with other testing tools

Built for Privacy-Conscious Teams

Convert is certified carbon neutral and has been recognized as a privacy leader among A/B testing platforms. It does not track individual visitors, does not use third-party cookies, and processes all data within the EU. For teams that need to run experiments on sites where Optimizely or VWO would create compliance concerns, Convert is purpose-built.

An Optimizely Alternative Built Around Not Collecting Data At All

Most of the compliance story in A/B testing is about where visitor data lives and who can reach it. ABlyft takes a different approach: it tries not to hold data that would raise those questions in the first place.

Privacy By Design, Not Just By Policy

From the product's own data-protection page:

No personal data or 'personal identifiable information' is stored. Neither IPs, user IDs or any individual information about the user. All data is stored aggregated and gives you all the information for your decisions.

We do not store IP addresses. Also, no user ID or the like is stored. Only aggregated data is stored -- i.e. no actions of a single visitor.

Self-hosting the JavaScript snippet is also offered as "a simple and secure self-hosting flow," which keeps the loading script itself off ABlyft's CDN if a customer wants that.

What It Does

• Visual editor for building experiments without code, alongside a developer-first API
• Server-side experiments as an option, not only client-side
• Cookie consent integration, respecting a site's own consent flow, plus a DoNotTrack honour setting
• Two-factor authentication and a change log recording every experiment modification
• AI features (ABlyft Lumen) available as an opt-in layer, not required to use the core product

Pricing

A Free plan is available with no credit card required. The Paid plan is quote-based rather than published, pitched around a proof-of-concept and tailored to customer needs.

German Entity, German Hosting, Thin Paperwork Around It

Operated by Conversion Expert GmbH, HRB 20453 (Amtsgericht Kiel), VAT DE325520659, Zeppelinring 52c, 24146 Kiel, Germany, CEO Alexander Richter. The compliance page states plainly: "We are German -- Hosting & whole Company in Germany" and "Hosting and Storage in Germany. All data and files are stored on highly secure servers."

What is missing is the paperwork that usually accompanies a claim like that. The published privacy notice is a generic, templated website-imprint policy covering cookies and server logs for ablyft.com itself, not a document addressing the SaaS product's own data flows, sub-processors or international transfers. No Data Processing Agreement was found published, referenced, or offered on request anywhere on the site -- for a company selling into "legal departments" as a stated audience, that is a real gap rather than a minor one, even with the no-PII architecture reducing what a DPA would need to cover.

Where It Fits

Against Optimizely, ABlyft trades enterprise scale and ecosystem breadth for a smaller, privacy-first German alternative. See also PostHog, AB Tasty, Convert Experiences and Kameleoon in A/B Testing.

Feature Flags First, Experimentation as One Use Case

Unleash is not built primarily as an A/B testing tool the way Optimizely, AB Tasty or Kameleoon are; it is a feature flag and progressive-delivery platform where A/B/n testing with flag variants is one of several use cases alongside gradual rollouts, canary releases and kill switches. For a team whose "experiments" are really staged feature rollouts with measurement attached rather than marketing-page optimisation, that is a meaningfully different tool than a visual-editor testing suite, and it belongs in this comparison for exactly that reason.

What It Does

• Unlimited feature flags, projects and environments on every plan, including the free open-source tier
• A/B/n testing with flag variants and user segmentation & stickiness
• Impact metrics, automated progression, and safeguards for rollout monitoring
• Four-eyes approval and change request workflows for flag changes
• 25+ official SDKs, with server-side SDKs evaluating flags locally so no end-user data leaves the customer's own infrastructure
• SOC2 Type II, ISO27001 and FedRAMP-track compliance on hosted Enterprise plans

Genuinely Open Source, Not Source-Available

The core is licensed AGPLv3 (Apache 2.0 for official Docker images and pre-v8 releases), self-hostable on Docker or Kubernetes, with no seat limit -- capped at 1 project, 2 environments and 5,000 feature flags per instance, which is a real ceiling but a workable one for most teams starting out. Thousands of teams reportedly run it in production this way with no bill at all.

Unleash Enterprise Pay-As-You-Go is $75/seat/month, billed monthly with a 14-day free trial and no contract; annual Enterprise is custom-quoted. Client-side monthly active users and flag evaluations are never billed on either tier, which matters for a tool whose whole job is being evaluated constantly in production.

EU or US Hosting -- A Real Choice, Not an EU Default

The pricing page states plainly: "Data residency options in the US or EU. Included [on both Pay-As-You-Go and annual Enterprise]." The published subprocessors page is more specific still: AWS is listed as a subprocessor for "Customer hosted instances. User accounts," located *"EU or US"**, with the footnote: "AWS Region depends on each customer selection. Options: Europe (Frankfurt) or US-East."

That means a European customer who wants EU-only hosting has to select it; it is not the default a customer gets by doing nothing, and two of the three named sub-processors -- Zendesk (support) and LogRocket (session recording, free-trial users only) -- are US-based regardless of which AWS region a customer picks. The Data Processing Agreement is thorough on the legal side of this: EU Commission Standard Contractual Clauses (2021/914/EU) are incorporated by reference for EEA, UK and Swiss transfers, with the relevant Module and Clause options specified rather than left vague.

Norwegian Entity, With a US Sibling for US Customers

Operated by Bricks Software AS, Edvard Storms gate 2, 0166 Oslo, Norway, for any customer located outside the United States. The Terms separately name Bricks Software Inc., 2261 Market Street STE 86259, San Francisco, CA, as the contracting entity for US-located customers -- meaning a European customer's contract is with the Norwegian entity specifically, not the US one. No document reviewed states which entity is the ultimate parent or how the two are related beyond both operating under the Unleash brand, so that structure is disclosed here rather than resolved.

Where It Fits

If the need is a visual page-optimisation editor, AB Tasty, Convert Experiences or Kameleoon fit that job more directly. If the need is flag-driven progressive rollout with experimentation layered on top, and a genuinely free self-hosted option matters, Unleash is the closer Optimizely alternative. See also PostHog for a product-analytics-plus-flags combination, and the wider A/B Testing category.