Uppy is brought to you by the people behind Transloadit and as such will have first class support for adding their uploading and encoding backend, but this is opt-in, and you can just as easily roll your own.
Design Goals:
Lightweight / easy on dependencies
ES6, with transpiled ES5 versions available
Usable as a bundle straight from a CDN, as well as a module to import
Resumable file uploads via the open tus standard
Robust: retries for all-the-things, avoid showing ‘weird errors’
Themable UI with a beautiful default
i18n support: Easily switch languages or supply your own copy
Compatible with React (Native)
Works great on mobile
Small core, modular architecture. Everything is a plugin
Works great with Transloadit. Works great without
Offering sugared shortcuts for novice users (presets)
Posted inDrag and Drop
The file uploader

the file uploader