abtest vs Experimently

abtest has no write-up on Specifiction yet; its figures are above.

Experimently is an open-source experimentation platform for A/B testing and feature flags that runs on infrastructure you manage. Its Free Preview costs nothing when self-hosted on your AWS account, with all features included; there is no hosted tier. The platform supports A/B and multivariate tests, sequential testing, CUPED, multi-armed bandits, Bayesian testing, split URL testing and LLM/model evaluation. Rollout controls include sticky assignment, staged rollouts, mutual-exclusion groups, a global holdout and automatic rollback based on error-rate and latency thresholds. Targeting offers more than 20 operators, while analysis includes frequentist and Bayesian methods, sequential mSPRT and segment breakdowns with Bonferroni correction. SDKs are listed for many programming languages and mobile platforms, but the maker says they are not yet on package registries; installation directions are in each guide. Deployment options include Docker Compose, Kubernetes through Helm, or an AWS CDK app for services in your AWS account. Assignment data stays on your infrastructure. Integrations include data platforms, business tools and email. The platform lists security and compliance features including role-based access control, SSO and audit logging.