realtime-bpm-analyzer is a TypeScript library that detects BPM (beats per minute) directly in the browser using the Web Audio API. It works on audio files, audio nodes, streams, and microphone input, with no server round-trip required.

The library is used by developers building music-related applications: DJ tools, music-reactive visualizers, fitness apps, producer utilities, and audio analysis tooling. It has 297 GitHub stars and thousands of weekly npm downloads. Apache-2.0 licensed. Solo-maintained since 2015, public on GitHub since 2018.

If your product depends on it, sponsorship is the most direct way to keep it healthy: triaged issues, reviewed PRs, timely releases, and ongoing compatibility with evolving browser audio APIs.

Where sponsorship goes

• Maintainer time — issue triage, bug fixes, PR review, releases.
• Infrastructure — CI, hosting, domains, testing devices.
• Continued development — performance work, API refinements, documentation.

Any amount helps. Recurring sponsorship is what makes maintenance predictable rather than something squeezed between other obligations.

Thank you to everyone who has supported the project so far — David.