React Native Performance API

react-native-performance is a library that brings a comprehensive implementation of the Web Performance API (User Timing Level 3 and Performance Timeline Level 2) to React Native applications. It provides high-resolution, monotonically increasing timestamps for accurate measurement, independent of system clock adjustments. The current stable version is 6.0.0, released in late 2024. The project maintains an active release cadence with frequent patch and minor updates, and major versions introducing breaking changes every few months. Key differentiators include its adherence to web standards, support for custom metrics, optional network resource logging (for fetch/XMLHttpRequest), and native marks for measuring core application startup and lifecycle events. It also offers the PerformanceObserver API for subscribing to performance entries and ships with full TypeScript type definitions.