FeatBit

What FeatBit does

FeatBit is a feature flag platform with a React dashboard and services written in .NET. It covers the usual flag work: boolean and multi-variant flags, targeting rules on user attributes, individual user targeting, percentage rollouts and reusable segments, organized into projects and environments. Flag insights show how often each variation is served during a rollout, and an audit log records every change.

It also has an experimentation module: you define metrics, attach a flag, and FeatBit analyzes the results with Bayesian statistics, including guardrail metrics that warn when a change makes something worse.

How evaluation works

Server-side SDKs evaluate flags locally from a cached copy of the rules. Client-side SDKs ask the Evaluation Server for results when they start. Changes are pushed to SDKs in near real time over WebSocket, with long polling as a fallback. The documentation states that data stays inside the FeatBit installation and is not sent to third parties.

Official SDKs cover .NET, JavaScript, React, React Native, Node.js, Java, Python and Go, plus OpenFeature providers; the iOS SDK is maintained by the community.

Self-hosting FeatBit

FeatBit runs as three containers: the UI, an API service and an Evaluation Server. The documentation describes three sizes:

• Standalone uses PostgreSQL for everything, including the message queue. This is what the default Docker Compose file starts.
• Standard uses PostgreSQL or MongoDB with Redis for caching and messaging, for higher traffic.
• Professional adds Kafka and ClickHouse for analytics on large volumes.

Kubernetes manifests, Helm charts and a Terraform setup for AWS are also provided. A relay proxy, FeatBit Agent, can run in a customer’s private network and sync flags from the main server. After installation, log in with the default test account and change its password.

The free self-hosted tier has no limits on seats, monthly active users or projects, according to the pricing page. The license-key features listed above, mostly governance and team features, need a paid Enterprise plan.

Hosted version

FeatBit Inc. runs FeatBit Cloud at app.featbit.co under a cloud services agreement; the same address is linked from the README as an online demo.

Limitations

The paid features include several that larger teams expect, such as SSO, change approvals and scheduled changes. The Professional deployment size brings Kafka and ClickHouse, which is considerably more to operate. The SDK list is shorter than those of the biggest projects, and there is no documented importer from LaunchDarkly, so a migration means recreating flags or scripting the REST API.

Who it suits

FeatBit suits teams, especially .NET shops, that want a self-hosted flag platform with experiments and no usage caps, and that can start small on a single PostgreSQL database. Compare Unleash and Flagsmith for broader SDK coverage, or GrowthBook for warehouse-based experiment analysis.