Unleash
The leading open-source feature management platform. Run fully self-hosted (free forever) or use the managed cloud. Supports gradual rollouts, user targeting, environment-based toggles, and A/B testing.
Why Unleash?
Need full control and self-hosting of feature flag infrastructure
GDPR compliance requires data to stay on-premise
Budget-conscious teams who want enterprise feature flag capabilities for free
Signal Breakdown
What drives the Trust Score
Download Trend
Last 12 months
Tradeoffs & Caveats
Know before you commitDon't want to manage infrastructure — LaunchDarkly or Statsig are fully managed
Need built-in A/B testing with auto-stats — Statsig is purpose-built for that
Very small project — the Unleash server has meaningful operational overhead
Pricing
Free tier & paid plans
Open source — self-hosted free forever
Managed cloud from $80/mo (Pro)
Enterprise features (SSO, SCIM) require paid plan
Alternative Tools
Other options worth considering
The industry standard feature flag and experimentation platform. Safe rollouts, A/B testing, and targeting rules for any deployment strategy. Used by thousands of engineering teams for risk-free releases.
Often Used Together
Complementary tools that pair well with Unleash
Learning Resources
Docs, videos, tutorials, and courses
Get Started
Repository and installation options
View on GitHub
github.com/Unleash/unleash
npm install unleash-clientQuick Start
Copy and adapt to get going fast
import { initialize, destroyWithFlush } from 'unleash-client';
const unleash = initialize({
url: process.env.UNLEASH_URL!,
customHeaders: { Authorization: process.env.UNLEASH_API_TOKEN! },
appName: 'my-node-app',
environment: process.env.NODE_ENV,
});
await new Promise((resolve) => unleash.on('synchronized', resolve));
const context = { userId: 'user_123', properties: { plan: 'pro' } };
const show = unleash.isEnabled('new-checkout', context);
console.log('Show new checkout:', show);
await destroyWithFlush();Code Examples
Common usage patterns
Docker Compose self-hosted setup
Run Unleash locally with PostgreSQL using Docker Compose
# docker-compose.yml
version: '3'
services:
unleash:
image: unleashorg/unleash-server:latest
ports: ['4242:4242']
environment:
DATABASE_URL: 'postgres://unleash:password@db/unleash'
DATABASE_SSL: 'false'
depends_on: [db]
db:
image: postgres:15
environment:
POSTGRES_DB: unleash
POSTGRES_USER: unleash
POSTGRES_PASSWORD: password
# Then run: docker compose up -d
# Admin UI: http://localhost:4242
# Default login: admin / unleash4allGradual rollout to percentage of users
Roll out a feature to 20% of users progressively
import { initialize } from 'unleash-client';
const unleash = initialize({
url: process.env.UNLEASH_URL!,
customHeaders: { Authorization: process.env.UNLEASH_API_TOKEN! },
appName: 'gradual-rollout-demo',
});
await new Promise((r) => unleash.on('synchronized', r));
// The gradual rollout strategy is configured in the Unleash UI.
// Here we just evaluate it with a user context (userId drives the hash).
function shouldShowFeature(userId: string): boolean {
return unleash.isEnabled('new-pricing-page', { userId });
}Community Notes
Real experiences from developers who've used this tool