Firefox's sync service is open source [1], so you can self-host it and update your about:config to point to it. I do this and it works great. (I believe you can

Firefox's sync service is open source [1], so you can self-host it and update your about:config to point to it. I do this and it works great. (I believe you can even self-host the accounts service if you really want to) Caveat is that I've linked to the old Python one, and they've got a new Rust one, but it didn't support SQLite the last time I had checked. [1] https://github.com/mozilla-services/syncserver https://github.com/mozilla-services/syncserver