Chrome Permission Audit

What is the activeTab permission in Chrome extensions? Security & privacy guide.

Learn how Chrome's activeTab permission works in Manifest V3, why it displays no install warning, and how user-triggered AI extensions use it to protect your browsing privacy.

Best fit

Best for users and developers who want to understand why activeTab is the gold standard for user-triggered browser extension access.

Technical Manifest Audit

Permission specification & risk profile.

Review how Chrome enforces activeTab in Manifest V3 and how to tell legitimate user-triggered extensions apart from intrusive tools.

Risk level: LoweractiveTab
Chrome install-time warning
None (displays no install-time permission warning in Chrome)
Manifest V3 declaration
{
  "manifest_version": 3,
  "name": "Example Reading Assistant",
  "permissions": ["activeTab", "storage"]
}
Legitimate uses vs. red flags
What to verify before granting this permission to an AI browser tool.

Legitimate AI reading uses

  • Reading selected text on the current tab after the user clicks the extension icon or presses a registered keyboard shortcut
  • Temporarily injecting an answer panel into the active tab in response to an explicit user gesture
  • Reading the current tab's URL and title only for the tab the user actively invoked

Red flags to watch for

  • Combining activeTab with broad background webRequest listeners that track non-invoked tabs
  • Sending the entire DOM of banking or password pages when the user only asked to define a single word
Step-by-step workflow

How to run this workflow in place.

1

Wait for a real user gesture

Under activeTab, the browser grants zero access to a tab until you press a keyboard shortcut, click the toolbar icon, or choose a context-menu item.

2

Scope access to one tab

Temporary access applies only to the currently focused tab and expires as soon as you navigate to a different origin or close the tab.

3

Verify what leaves the browser

Even when tab access is user-triggered, check the extension's privacy policy and context settings to confirm only your selection and chosen context are transmitted.

Key details

Why this approach works better than switching tabs.

Why Chrome created activeTab
Before activeTab, extensions that needed to work on any website had to request permanent host permissions across all URLs—even if the user only clicked the extension once a week.
  • Grants temporary host permission to the active tab only after an explicit user gesture
  • Prevents background scripts from silently reading tabs you haven't interacted with
  • Automatically revokes access when the tab navigates to a new domain
When AI extensions need more than activeTab alone
Many in-page AI overlays also register content scripts so custom keyboard shortcuts, selection listeners, and floating UI styles respond immediately inside the page.
  • Custom in-page keybindings (beyond Chrome's 4-shortcut global command limit) require an active content script
  • When content scripts are used, the crucial security check is whether network requests are strictly gated behind a user trigger
  • Open Chrome DevTools -> Network tab to verify an extension makes zero outbound requests during normal page loads
Frequently asked questions

Common questions about chrome permission audit.

Can an extension with only activeTab read my browsing history?

No. The activeTab permission only grants temporary access to the single tab where you explicitly triggered the extension (via keyboard shortcut, toolbar click, or context menu). It cannot see other open tabs or past history.

Why do some AI extensions ask for host permissions in addition to activeTab?

If an extension renders an instant in-page overlay with custom keyboard shortcuts on any webpage, it often declares content scripts in manifest.json. When auditing those extensions, verify that they never transmit page data until you explicitly trigger a query.

How can I restrict any Chrome extension to behave like activeTab?

Right-click the extension icon in Chrome, select 'Manage Extension', and change 'Site access' from 'On all sites' to 'On click'. Chrome will then block the extension from running on any page until you click it or press its shortcut.

Related workflows & guides

Explore connected pages.

Available for Chrome and Firefox

Ready to try this workflow on your own reading?

Install Vezz me free, highlight text on any webpage, and press your customizable shortcut (default: Ctrl+Shift+X or Cmd+Shift+X on Mac) to get an answer right beside the source.