Here's some recent threads where this was already asked:<p><a href="https://news.ycombinator.com/item?id=22534520" rel="nofollow">https://news.ycombinator.com/item?id=22534520</a><p><a href="https://news.ycombinator.com/item?id=13721664" rel="nofollow">https://news.ycombinator.com/item?id=13721664</a><p><a href="https://news.ycombinator.com/item?id=16050294" rel="nofollow">https://news.ycombinator.com/item?id=16050294</a><p><a href="https://news.ycombinator.com/item?id=20204018" rel="nofollow">https://news.ycombinator.com/item?id=20204018</a>
Bitwarden <a href="https://bitwarden.com/" rel="nofollow">https://bitwarden.com/</a> Firefox extension, standalone desktop app, CLI. Could be self-hosted (third-party). Most of it is Open Source.
Locally hosted version of <a href="https://app.keeweb.info" rel="nofollow">https://app.keeweb.info</a> configured with a cloud storage provider.