Expose a persistent per-tab identifier for extensions that survives Chrome restarts and tab restore

[Ahmed Aqil]

I am developing a Chrome extension for tab-specific notes. The core requirement is that every browser tab should have its own independent notes, even when multiple tabs have exactly the same URL, title, or other visible properties.

For example, a user may have five YouTube tabs open at the same time. Each tab should have its own notes, and those notes should remain attached to the correct tab after Chrome is closed and reopened.

The current chrome.tabs.Tab.id does not solve this because it changes when Chrome restarts and restores the tabs. Extensions therefore have to guess which newly created tab corresponds to which previous tab using URL, index, title, history, and other properties. This is inherently unreliable when users have duplicate tabs or make changes to their tab layout.

I would like Chrome to provide an officially supported, persistent per-tab identifier or persistent tab metadata that:

• Remains associated with the same restored tab across browser restarts.
• Is accessible to authorized extensions.
• Remains unique even when multiple tabs have the same URL and title.
• Survives normal tab restoration and browser session recovery.
• Is not tied only to the current tab.id runtime identifier.

Allows extensions to reliably associate user data, such as notes, with the correct tab.

This would enable extensions to implement reliable tab-specific features such as notes, reminders, annotations, reading state, task context, and other personal metadata without having to reconstruct tab identity heuristically.

This capability would be particularly useful for users who keep many tabs open and need a way to remember why each individual tab was opened.