Group Tabs by Domain

Puts tabs from the same site into a group named after it, like example.com. It groups once, each time you choose it.

Use it

Right-click a tab and choose Group Tabs by Domain, or choose Tabs → Group Tabs by Domain. It groups the tabs in the front window. Press ⌘Z right after to put them back where they were.

Turn it off

It's on by default. To take it out of both menus, open Dia → Settings → Patches and switch off Group Tabs by Domain. Or run:

diatweaks disable groupTabsByDomain

FAQ

Does it read my pages?

No. It only looks at each tab's address.

Which tabs does it leave alone?

Pinned tabs, tabs already in a group, new tab pages, files and Dia's own pages. A site needs at least two tabs to get a group.

What if I already have a group for a site?

If a group's name is exactly the site, like example.com, that site's tabs join it instead of making a new group.

Are www.example.com and example.com the same site?

Yes, it ignores www.. Other subdomains, like docs.example.com, get their own group.