LaunchDarkly and Split.io meter usage by monthly active users or evaluation contexts, and even open-core options like Unleash gate SSO, RBAC, and audit logs behind a $75-per-seat Enterprise tier with a five-seat minimum. PostHog's hosted plan follows the same pattern past its free 1 million flag requests, charging per request once a team wires flags into every microservice, mobile client, and edge worker. Running Flipt, FeatBit, GrowthBook, Flagsmith, Unleash, and PostHog on your own infrastructure moves flag evaluation inside your network boundary: Flipt reads flag state straight from Git with no database call leaving your CI/CD pipeline, GrowthBook's stats engine queries your own Postgres, BigQuery, or Snowflake warehouse directly, and FeatBit's standalone mode runs on a single Postgres container inside a custom Docker Compose stack instead of a vendor-managed Kafka/ClickHouse pipeline.
| Name | Main Category | Sub-Category | Target Alternative | Free Tier Summary | Self-Hostable? | Short Description | Primary Link |
|---|---|---|---|---|---|---|---|
Flipt | DevOps & Application Hosting | Feature Flag & GitOps Delivery | LaunchDarkly / Split / ConfigCat | 100% Free - Self-Hosted (GPL-3.0 server, MIT client SDKs) | Yes - Binary | Single Go binary that stores flag definitions in Git and evaluates them locally over gRPC, so flag changes ship through the same PR and CI/CD workflow as application code with no external database required. | |
FeatBit | DevOps & Application Hosting | Feature Flag & A/B Testing | LaunchDarkly / Split | 100% Free - Self-Hosted (MIT core; enterprise features separately licensed) | Yes - Docker | MIT-licensed, .NET-native feature flag service with a standalone deployment mode that runs on a single Postgres container instead of the full Kafka/ClickHouse pipeline used at scale. | |
GrowthBook | DevOps & Application Hosting | Feature Flag & Experimentation Platform | LaunchDarkly / Optimizely / Amplitude | 100% Free - Self-Hosted (MIT open-core; enterprise directories separately licensed) | Yes - Docker | Warehouse-native feature flags and A/B testing that query your own Snowflake, BigQuery, Postgres, or ClickHouse connection directly instead of exporting events to a vendor. | |
Unleash | DevOps & Application Hosting | Feature Flag & Release Management | LaunchDarkly / Split / Optimizely | 100% Free - Self-Hosted (Apache-3.0 core; OSS capped at 1 project / 2 environments, unlimited flags) | Yes - Docker | Open-source feature flag server with 30+ official SDKs, gradual rollouts, and custom activation strategies; the OSS edition runs as a standalone Node.js service backed by your own Postgres instance. | |
Flagsmith | DevOps & Application Hosting | Feature Flag & Remote Config | LaunchDarkly / ConfigCat | 100% Free - Self-Hosted (BSD-3-Clause) | Yes - Docker | Combines feature flags with remote configuration and user-trait segmentation; ships as a Django API plus Postgres in a docker-compose stack you fully control. | |
PostHog | DevOps & Application Hosting | Feature Flag & Product Analytics | LaunchDarkly / Amplitude / Split | 100% Free - Self-Hosted (MIT core; ee/ enterprise directory separately licensed) | Yes - Docker | Bundles feature flags with session replay, product analytics, and experimentation on a self-managed ClickHouse-backed stack, avoiding per-request flag pricing once deployed on your own cluster. |