Marginalia is a Chrome extension that lets you highlight text on any webpage, jot a note in the margin, and find it again later. This page explains what data the extension handles, how it's stored, and why each browser permission is required.
The short version: Marginalia has no servers, no analytics, and no tracking. Everything you highlight or write stays on your device, inside your browser's local storage.
Information Marginalia Stores
When you highlight text or add a note, Marginalia saves the following directly on your device:
- The highlighted text itself
- Any note you write for that highlight
- The color/tag you chose for the highlight
- The URL and title of the page the highlight was made on, so it can be re-applied and so you can jump back to it
- The date and time the highlight was created
This data is only created when you select text and choose to highlight or annotate it. Marginalia does not read, scan, or record any other content on the pages you visit.
How Your Data Is Stored
All of the information above is saved using chrome.storage.local — Chrome's built-in local storage for extensions. This means:
- Your highlights and notes are stored only on your own device
- Marginalia does not have a server, database, or backend of any kind
- Nothing is transmitted over the network, to Srikanth Badavath, or to any third party
- No analytics, advertising, or tracking SDKs are included in the extension
Exporting Your Data
Marginalia lets you export your highlights and notes as Markdown or CSV. This export happens entirely on your device — the file is generated locally and saved to your computer through your browser's normal download flow. It is never uploaded anywhere by the extension.
Permissions Marginalia Requests
Chrome requires extensions to declare upfront which permissions they need. Here's what Marginalia uses and why:
| Permission | Why it's needed |
|---|---|
storage | Save your highlights and notes locally using chrome.storage.local. |
host_permissions: <all_urls> | Lets the highlighter run on any website you visit, since highlights can be made on any page. |
all_frames | Allows highlighting inside embedded frames (for example, the message view inside Gmail), not just the top-level page. |
activeTab / tabs | Used to read the current tab's URL and title (to label and re-find your highlights) and to scroll back to a saved highlight when you click it from the popup. |
Data Retention & Deletion
- You can delete any individual highlight or note at any time from within the extension.
- Clearing your browser's extension storage, or uninstalling Marginalia, permanently removes all data it stored.
- Because nothing leaves your device, there is no copy of your data anywhere else to delete.
Children's Privacy
Marginalia is not directed at children and does not knowingly collect any information from anyone, including children under 13.
Changes to This Policy
If this policy changes, the "Last updated" date at the top of this page will be revised. Since the extension has no servers or accounts, any change would only ever relate to how local data is handled on your device.
Contact
Questions about this privacy policy or Marginalia can be sent to badavathsrikanth149@gmail.com, or filed as an issue on the GitHub repository.