Real-Time Feature Flags

Feature flags evaluated in microseconds, updated instantly

Feature flags without remote requests
Feature Flags Served
Without Remote Requests
No synchronous HTTP requests when evaluating a feature flag. No latency for your users.
Real-time feature flag / feature toggle updates
Flag Updates
LaunchDarkly streams flag rule updates to your app in real-time.
Latest feature flag / feature toggle rules evaluated in memory
Flags Evaluated
in Memory
Requesting a feature flag reads the latest flag rules from memory.
Streaming Architecture Works in Microseconds
LaunchDarkly uses a streaming architecture to serve feature flags without making remote requests. We use server-sent events (SSE), a protocol for one-way real-time messaging, to send messages to your servers whenever you change the feature flag rules on your dashboard. SSE is widely used for server-to-browser messaging and works equally well for server-to-server communication. The SSE connection is all handled automatically by our SDKs. We have a SDK for all major languages.
Feature Flags in Microseconds
Enterprise-Grade Reliability with Layered Redundancy
Reliability with Layers of Redundancy
LaunchDarkly’s streaming architecture ensures that feature flags are updated instantly, without introducing any latency to your site. LaunchDarkly's performance is even faster than storing feature flags in your own database. Fast performance is important, but so is reliability. We have multiple layers of redundancy. All flags are served locally, and then we have two layers of globally distributed CDNs. A feature flag will always be available.