Here are some drum machines online..that are free.
https://drumbit.app/ Drum it app
https://www.virtualdrumming.com/drums/virtual-drum-machine-online/drum-machine-online-free.html virtual drum machine
https://www.musicca.com/drum-machine?data=90-n-44-a--5acegikmo6em7ai-
https://wambox.net/ wambox
Synthesizers
https://www.websynths.com/microtonal/ websynth
https://nicroto.github.io/viktor/ viktor synthesizer
https://midi.city/ midi city synthesizer
https://synth.playtronica.com/ online synthesizers playground list
Keyboard Synthesizer
https://sodaphonic.com/instruments/synth Sodaphonic
https://chosenmasters.com/online-synth Chosenmasters synth
https://www.gsn-lib.org/apps/cardboardsynth/index.html cardboard synth
https://onlinesequencer.net/ online sequencer
https://www.melomaker.com/ melo maker