MSW (Mock Service Worker) is a seamless API mocking library for browser testing and development. It intercepts network requests at the browser level, allowing you to define mock responses without touching your application code. This facilitates faster, more reliable tests and improves development workflows by simulating various API states and edge cases, independently of a backend.
MSW's release frequency varies. In 2024, March, September, and October had the most releases (9-13 versions). Release frequency decreased toward the end of the year. In 2025, January and March had no releases, while May saw a spike (9 versions). The most recent data for August 2025 shows only one release.
MSW's npm downloads show strong growth throughout 2024 and 2025. Downloads surged from February 2024 to a peak in July 2025. August 2025 data, being incomplete, shows a decrease, but the overall trend indicates increasing popularity and adoption of the library.
