Sync between browsers/devices without a server

[strdr4605]

WebRTC and STUN Servers look like a good option for creating a connection between 2 clients.

Maybe use try https://peerjs.com/

[kuchta]

For WebRTC or custom STUN networking, you need at lease 2 devices online at the same time for it to sync. PeerJS AFAIK currently doesn't have any solution for renting a persistent decentralized storage space so if you don't want to run your own infra, you probably also can't sync between devices that are not online at the same time. Fireproof on the other hand has native support for in-app renting of storage through web3.storage and web3.storage/storacha.network offers first 5GiB of space for free. See https://use-fireproof.com/docs/connect#ipfs