Real-time pitch detection in the browser — how it works and a free tool to try it

Ever wondered how a tuner app knows what note you're playing? The underlying tech is surprisingly accessible in modern browsers — no native app, no plugins required. How browser-based pitch detection works Modern browsers expose the Web Audio API , which gives you access to the microphone via getUserMedia() . Once you have an audio stream, you can run pitch detection algorithms on the raw frequency data. The most common approaches: 1. FFT (Fast Fourier Transform) The Web Audio API's AnalyserNode