Earlier today I received this question on Twitter:
@rmbyrne hi!! is there a free sound editor similar to audacity but online? To add music, effects still seems to require software. THANKS:)!!
— Sonia Guilana (@sguilana) March 24, 2017
My suggestions were to try SoundTrap, BandLab, or Soundation.
Soundtrap is a fantastic tool for creating music online. The cool thing about Soundtrap is that students can use virtual instruments to create music or they can record themselves playing music on an instrument and then use that recording in conjunction with the virtual instruments in the Soundtrap environment. What makes Soundtrap stand-out from the crowd is its collaboration options. Click the “collaborate” tab in the Soundtrap editor to invite others to create music with you. Soundtrap will work in the Chrome web browser on a laptop, iPad, Chromebook, and Android tablet. In my workshops I often describe Soundtrap as Google Docs for music.
BandLab is a free service that enables you to create music in your web browser or through free Android and iOS apps. In BandLab’s you can create soundtracks using any of the virtual instruments that are provided. You can also speak or sing to record a track. Within the BandLab editor you can mix your tracks together to create a song. If you have existing audio files on your computer, you can upload those to incorporate into your BandLab creations.
Soundation is a service that allows anyone to create and remix sound tracks online. If you have used Apple’s Garage Band, Soundation will look familiar to you. Soundation provides tracks on which you can place music clips and sound effects to mix together. To create your original work you can select from Soundation’s gallery of 400 free sounds, upload your own sounds, or record new sounds using the instruments and keyboard built into Soundation. When you’ve created a product you like, you can download it or share it in Soundation’s gallery.