Tab Organizer automatically groups tabs in two ways:

1. By domain or subdomain: This is a quick setup - just check a box in the settings, and you're ready! Tabs are automatically grouped based on their (sub)domain names, so all tabs from the same site are together.

2. Custom rules: This offers more flexibility and context. You can create rules like grouping all tabs with domains containing "amazon," "ebay," or "walmart" into a "Shopping" group, or those with titles containing "yoga," "fitness," or "sport" into a "Health" group.

With the latest version of Tab Organizer, tabs saved in Spaces are securely stored on our servers so you can access and organize them across sessions and devices. We store only the minimum information required for this feature to work and follow industry best practices to protect your data.
We do not track your browsing activity or sell your data.
Tab Organizer does not monitor your browsing behavior, and no data is collected beyond what’s necessary to provide the tab-saving functionality.

Tab Organizer does not group pinned tabs intentionally considering them as "something that should be untouched".

In this case tab group is created based on the 1st matched rule.

Rules matching have a higher priority than (sub)domain matching so a group is created based on the 1st matched rule. If no rule matches then a group is created based on (sub)domain.