Keepassxc and syncthing.

I sync two databases across Mac, linux, ipads, and android phones. One for work, one for personal.

If you are alone and have reliable internet, then syncing the password db file can be good enough.

I mean you can only run into a problems when you change it in two devices without sync in between. But that is super unlikely (in general; if you have reliable internet; you can improve reliably of this setup by syncing to a kind of server/file storage as "source of truth" as it won't be e.g. out of battery or disconnected from the internet ;-) ).

And as long as what you use for syncing doesn't blindly overrides when conflicting syncs happen you can resolve the problem by hand, not that I would expect it to happen. (At least with KeePassXC this works well, I haven't use keepass as most places strongly recommend XC over keepass without XC.)

Not keepass, but you can self-host Bitwarden using `vaultwarden`, an open-source reimplementation of the server (the official server is also partially open source, but complex to install and run - this one is a simple binary you can run), which works with the official client apps.

I use resilio sync to sync my keepass file and it's working out pretty well. https://www.resilio.com/individuals/

A few year ago I was syncing keepass over http (it's built in keepass) with a Apache httpd and webdav module. Configuration was not really tricky and worked flawlessly. I even managed to use a yubikey on sync request.

I just use keepassxc and have a cron job that zips and encrypts the password vault and then uploads it to Amazon S3 once a day, simple and pretty much foolproof, probably costs me $0.12 a year for storage.

I use WebDAV. Just throw up a container like dgraziotin/nginx-webdav-nononsense and connect to keepass2android and keeweb. I then use regular backup software to back up the mounted WebDAV files.

password-store is another solution if you're CLI and scripting inclined. It also has browser plugins. KeepassXC + a cloud "dropbox", make sure that it is set to save after every change to the password database. It also has plugin for popular browsers. Vaultwarden is another option and the one I am likely to switch over to after this announcement.

Use syncthing on a folder with the database

I sync over SFTP to a VPS. Works with Keepass2Android on mobile too, I've used this for several years now.