Set exactly where new tabs open, independently for each way you open them:

Link clicks (middle-click, Ctrl+click, target=_blank) - open right of the current tab by default
Blank new tab (Ctrl+T, the + button) - independently configurable
Reopened tabs (Ctrl+Shift+T) - independently configurable

Each trigger can be set to: Right of current, Left of current, End of strip, Beginning of strip, or Firefox default. Extra controls, all optional:

Focus when opening: decide whether new link-click or blank tabs open in the foreground or background. Useful if you want to queue up links without losing your place.
After closing a tab, activate: choose which tab gets focus next: the left neighbour, right neighbour, the tab that opened the closed one (the opener), the last tab you used before this one, or Firefox's default.
Join opener's tab group: tabs opened from a link inside a grouped tab automatically join that group (requires Firefox 138 or later, where tab groups are available).

Prevent duplicate tabs: if you middle-click a link that is already open somewhere in the window, Anchrd Tabs switches to the existing tab instead of opening a second one. How it works Anchrd Tabs runs entirely as a background event page. It has no access to page content - it only reads tab metadata (position, URL, group membership) to decide where to place new tabs. All settings are saved via Firefox Sync, so your preferences follow you across devices. Anchrd Tabs requires Firefox 115 or later. Privacy

No data is collected, stored externally, or transmitted anywhere.
No analytics, no telemetry, no third-party libraries.
No host permissions - Anchrd Tabs never touches the content of any web page.
The only permissions declared are: tabs, storage, and sessions - each used directly for the features described above.

Full privacy policy: https://griffentek.github.io/anchrd/privacy