How music recognition works
A recording has a kind of fingerprint: the pattern of its loudest sounds over time. A recognition system stores these patterns for each song, then looks for the same pattern in what your microphone hears. It works through some background noise, because it only needs part of the pattern to line up.
Why humming is a different problem
A hum has none of the original sound, so a fingerprint can't match it. Instead, HumFinder compares the shape of your melody, the ups and downs from note to note, with the melodies of its songs. That is why a hum gives a shortlist to check, not one certain answer.
Using it in your browser
Press Listen to music on HumFinder and allow the microphone when asked. It listens for up to twelve seconds, and stops as soon as it finds a match. Your browser turns the sound into a fingerprint on your device, and only that fingerprint is sent, encrypted.
App or website?
Apps like Shazam can be quicker to reach on a phone and know far more popular songs. A website means nothing to install, and it also works on a computer. HumFinder's catalogue is smaller and mostly holds independent releases for now, so it won't know many popular songs yet.