A real-time analyser in a browser tab.
A real-time audio analyser that runs entirely in a browser tab: an RTA from 1/3 to 1/48 octave, a spectrograph sharing its frequency axis, and a full-height meter with peak, RMS, peak hold and broadband Z/A/C. The transform chain is pinned down by tests at every size and window, and the built-in pink noise source is there so you can check it reads level properly before you believe anything it tells you about a room.
simpleRTA runs in the browser and needs JavaScript.