This tool receives microphone input and determines the note name, octave, and pitch while printing the notes every half second and visualizing the noise
Connect a microphone to the website by ensuring the browser is up to date and has proper permissions. Then, with the smallest possible background noise: sing, whistle or play whatever sound you wish to determine the note of and read the information displayed within the block.
Keep in mind that the sharp version of one note (C#) is the same as the flat version of the next note one half-step higher (Db). The reason there is only one note printed was purely to save space.
This tool can be used to find anything with a clear pitch, including whistling, tuning an instrument or even singing if you're into that kind of thing. I've been told it also works very well for finding your vocal range without having to use a dedicated source. All in all, its good at resolving anything with a clear, simple waveform so don't get discouraged if your loud relatives are messing with your harmonics.
The note and pitch element was made with a heavily modified version of the GitHub project by Chris Wilson. Super clever stuff on his part.
It works by taking live microphone input and running an auto-correlation algorithm. It will find the pitch with the best-fit realtime and then extract a note based scientific pitch notation. A separate method determines the octave and adds it as a subscript to the note from the same log2 formula. That means whatever note is clearest at the time will be displayed. You can see the individual notes printed on the bottom, left to right, which may have been the most satisfying thing I've ever made. If you want to check out the code, please do so by all means. If you want to use it just make sure to give credit.