Category
Feature Flag APIs pricing
Feature flag APIs let developers decouple deploys from releases, toggling features, running progressive rollouts, targeting cohorts, and running experiments via SDKs and a management/evaluation API. The category splits between experimentation-heavy incumbents (LaunchDarkly, Split, Optimizely), product-analytics platforms that bundle flags (PostHog, Statsig), and open-source / developer-first challengers (Flagsmith, ConfigCat, Unleash). Compare on documentation and DX, reliability and SLA maturity, SDK/ecosystem breadth, and how fast a developer or AI agent can self-serve a working key. Watch pricing models closely: per-seat (LaunchDarkly, Split), per-MAU/MTU (Statsig, Optimizely), per-request (PostHog, Flagsmith), and flat-tier (ConfigCat) diverge sharply at scale.
| API | Billed by | Free tier | Verified |
|---|---|---|---|
 LaunchDarkly Feature Flag APIs | Per-seat + MAU-based | Free tier or trial | Jun 27, 2026 |
 Statsig Feature Flag APIs | Per metered event / MTU-based | Free tier or trial | Jun 27, 2026 |
 PostHog Feature Flag APIs | Per request (volume-tiered) | Free tier or trial | Jun 27, 2026 |
 ConfigCat Feature Flag APIs | Flat tier (config fetches) | Free tier or trial | Jun 27, 2026 |
 Split Feature Flag APIs | Per-seat (usage-based at scale) | Free tier or trial | Jun 27, 2026 |
 Flagsmith Feature Flag APIs | Per request (API calls) | Free tier or trial | Jun 27, 2026 |
 Unleash Feature Flag APIs | Per-seat (cloud) / OSS self-host | Free tier or trial | Jun 27, 2026 |