The best alternatives to io808 are HTML-909 Rhythm Composer, Ocean beta, and BEET. If these 3 options don't work for you, we've listed a few more alternatives below.
What do you think of io808?
AssemblyAI— Speech-to-Text API with superhuman accuracy
Ocean lifts the barriers that are often associated with electronic music-making & enable people to enjoy making music, exploring sounds and collaborating with people globally.
Think you can finger drum? Think again. BEET is the finger drumming game that puts your grooviness to the test. Play over 200 spicy beats designed by real producers.
A website for making and sharing music box songs. It's free to use and doesn't require an account to make and share songs (all song data is stored in the URL).
Howdy folks! I got frustrated trying to find interesting classical music concerts to go to, so I built Classical Page. You choose which works and composers you are interested in, and Classical Page emails you when new concerts are listed.
PIXELSYHTH is a browser-based synthesizer for creating sounds from images and drawings. Powered by Web Audio and JavaScript, PIXELSYHTH lets you draw shapes and lines to create your very own sounds. Pop in some headphones, and enjoy the thing you created.