Flagsmith

Flagsmith is an open source feature flag and remote configuration platform that enables development teams to ship features fearlessly with fine-grained control over releases. The platform provides an all-in-one solution for developing, implementing, and managing feature toggles across web, mobile, and server-side applications. Core capabilities include feature flags that wrap code sections with toggle logic, enabling or disabling functionality without code changes or deployments. Granular segmentation rules allow targeting individual users, specific user segments based on stored traits, or percentage rollouts for canary deployments. Multivariate flags support A/B and multivariate testing with percentage splits across two or more variations, integrating with existing analytics platforms for experimentation. Remote configuration combines feature toggles with configurable values, allowing real-time application changes like payment options or UI colors without deployment or app store approval. User traits and segmentation enable strategic feature rollouts to power users, internal teams, or early adopters based on behavioral data. Change tracking provides full audit logs of all modifications, with one-click rollback when issues arise. The platform offers three deployment options: enterprise-grade SaaS cloud optimized across eight global regions, fully managed private cloud in any chosen region, and self-hosted on-premises with Helm charts for Kubernetes and an OpenShift Operator. OpenFeature compliant. SDKs are available for thirteen languages and platforms including React, React Native, Next.js, Node.js, Android, iOS, Flutter, Python, Ruby, .NET, PHP, Go, Rust, and a REST API. GDPR compliant with SLA guarantees. Trusted by Okta, Citi, Ford, OakNorth Bank, SunRun, Vontobel, Creditas, Wistia, and Delinea. Released by Bullet Train Ltd under a BSD-3-Clause open source license.