This should play if your Web browser has WebAssembly enabled (most do). Most examples will play unless they need to load files. The first time you click Play, Csound will spend a few seconds loading, then play. You can edit this code and replay it.
-o dac ; Required settings for WebAudio: sr = 48000 ksmps = 128 nchnls = 2 nchnls_i = 1 instr 1 a1 diskin "fox.wav" a2 ftconv a1, p5, 256 out a2*p4 endin ; impulse response f1 0 131072 1 "ir.wav" 0 0 1 ; minimum-phase version f2 0 131072 53 1 3 ; Hann window f3 0 1024 20 1 1 ; low-pass frequency response f4 0 1024 7 0 100 0 24 1 900 1 ; low-pass linear-phase IR f5 0 2048 53 4 4 3 ; scale IR i1 0 3 0.25 2 i1 + 3 1 5