Peer-to-peer file transfers in your browser Cooked up by Alex Kern & Neeraj Baid while eating Sliver @ UC Berkeley.
Using WebRTC, FilePizza eliminates the initial upload step required by other web-based file sharing services. When senders initialize a transfer, they receive a “tempalink” they can distribute to recipients. Upon visiting this link, recipients’ browsers connect directly to the sender’s browser and may begin downloading the selected file. Because data is never stored in an intermediary server, the transfer is fast, private, and secure. (Your PC must be online while the recipient download the file(s), if you shutdown the PC or goes offline, the download also stops)
You can selfhost it or use the official instance
If you are talking about WebPush, technically the browser company provides the backing server
That’s a good point, I worded it poorly. The backing server is provided by you (via your browser). In theory you could run your own or whatever you want. But all traffic is encrypted so it doesn’t matter much who runs it.