Bitwarden Auto-fill and simple hosts

23 Mar 2025 13:33 bitwarden

I use Bitwarden for managing my passwords. When using the Firefox browser extension, it refused to autofill the credentials for my Synology NAS. Here’s how I fixed it.

My Synology NAS is at https://diskstation:5001. When I browse to it, Bitwarden doesn’t recognise the site, so it doesn’t offer to auto-fill the username and password. No matter how many times I selected “Autofill and Save”, Bitwarden never seems to remember the site. I always have to search for the relevant entry and copy the username and password explicitly.

I finally looked into it this weekend.

It turns out that the default setting for auto-fill’s match detection is “Base domain”. It seems like this breaks in the face of host-only URIs, such as the one I’m using with my NAS.

To fix it:

  1. Search for the relevant login entry and click Edit.
  2. In the Auto-fill options section, click the cog (settings) icon next to the first URI.
  3. Set Match detection to “Host”.
  4. Save your changes.

The browser extension now correctly matches the URI (so I get the little “1” badge on the icon), and the “Fill” button appears and works.