A small Chrome extension that changes tab placement behavior inspired by Arc and Dia.

Tab placement

• New tabs open at the top of the unpinned tab section. This includes externally opened URLs
• Links opened from pinned tabs also open at the top of the unpinned tab section.
• Links opened from unpinned tabs open immediately below the opener tab.
• Links opened from grouped tabs are added to the same tab group and placed immediately below the opener inside that group.
• Duplicated tabs open immediately below the tab being duplicated.

Automatic tab group creation:

• If you open 2 or more links from the same ungrouped tab within 2 minutes, those tabs are treated as related and grouped automatically, similar to Dia's auto tab grouping behavior.
• If closing a tab leaves only one tab in a tab group, that remaining tab is automatically ungrouped and left open.
• The tab group name is automatically set based on the source tab and prefixed with a random emoji. -- If the local Gemini Nano model is downloaded, it creates the tab group emoji and name.
• If the source tab is pinned, the pinned tab stays pinned and only the related child tabs are grouped.

During Chrome startup/session restore, the extension preserves Chrome's restored tab order and restored tab groups instead of applying new-tab placement to those restored tabs.

Chrome does not expose an API to scroll the tab strip after an existing tab is moved, so simply moving a new active tab to the top leaves the strip parked at the bottom. To keep the strip scrolled to the new tab, the extension instead recreates an active new top tab directly at the top index (creating a tab at an index makes Chrome scroll to it). Blank new tabs are recreated as your default new tab page; an externally opened link is reopened once at the top. Tabs opened in the background, and privileged URLs the extension can't reopen, are still moved rather than recreated.

For the smoothest new-tab behavior, use the extension command:

• Default: Alt+Shift+T
• macOS: Option+Shift+T

That command creates the tab at the top index directly in one step, with no reposition or reload. Chrome does not allow extensions to override the built-in Cmd+T shortcut, but you can change extension shortcuts at chrome://extensions/shortcuts.

1. Open chrome://extensions.
2. Enable Developer mode.
3. Click Load unpacked.
4. Select this folder.
5. Open the extension's Details page and click Extension options to check or prepare the local Gemini Nano model.

Permissions

• No host permissions are requested, and the extension does not read page content.
• The webNavigation permission is used only to receive the source tab ID for tabs created by link navigation.
• The tabs permission is used only to read tab metadata for naming automatically created groups and detecting duplicated tabs.
• The tabGroups permission is used only to name and color automatically created groups.
• The storage permission is used only to remember one expiring timestamp for the brief startup/session-restore guard.
• Gemini Nano naming uses Chrome's local Prompt API; tab titles and hostnames are not sent to the Gemini web API. Chrome may download the local model once if it is supported but not already installed.

Source code is public. So you can read yourself/have your agent investigate.