Unleash
Open-source feature flag platform, self-hostable under Apache 2.0.
About
Unleash is the leading open-source feature management platform, built in Oslo by Ivar and Egil Osthus after Ivar open-sourced his internal flagging tool from FINN.no in 2015. The Apache 2.0 core gives teams gradual rollouts, targeting strategies, variants for A/B testing, and change request workflows, all self-hostable inside their own infrastructure with full auditability, which is why regulated enterprises like Visa, Lloyds Bank, and Samsung run it.
The commercial Unleash platform adds enterprise scale, and in 2026 the company raised a $35M Series B while launching Impact Metrics to govern feature rollouts at AI speed, arguing that AI-generated code shipping faster makes runtime control more critical, not less. With 45M+ Docker downloads, Unleash is the default answer for teams that want LaunchDarkly-style feature ops without a closed SaaS dependency. GitLab never acquired Unleash; it only ships an Unleash-compatible legacy flag API.
What it can do
- Gradual rollouts with targeting strategies
- Variants for A/B testing and experimentation
- Self-hosted Apache 2.0 core with audit logs
- Impact Metrics for AI-speed rollouts
- Official SDKs for all major languages
Setup
Self-host with Docker or use Unleash hosted; add a client SDK to your app and define flags in the admin UI.
Prerequisites
An application to flag; a Postgres database for self-hosting.
Use cases
Works with
Trust score — 7/10
Scored 7/10 (metrics tier, metrics-v1). Evidence: Verified via vendor site/docs/GitHub and reputable coverage, wave 88; Trending score 72/100 from researcher assessment.
Sources
Every fact above was checked against these sources. Where a claim comes from the provider and couldn't be independently verified, the text says so.