Privacy Policy — Marginalia

PDF Highlighter & Video Notes · Last updated 28 October 2026

Marginalia stores your notes on your own computer. Nothing is sent anywhere. There is no server, no account, no analytics, and no advertising. The developer cannot see your notes.

What Marginalia stores

When you highlight a passage or write a note, Marginalia saves it using Chrome's local extension storage (chrome.storage.local) on your device. A saved record contains:

• the text you typed
• for PDFs: the page number, the passage you highlighted, and the position of the highlight on the page
• for videos: the timestamp you marked
• the address and title of the document or video, so the notebook can be labelled and reopened
• an identifier for the document — for PDFs a one-way hash of the file's contents, for videos the video's identifier on its platform

The two categories this involves

Chrome asks extensions to declare the kinds of data they handle, even when that data never leaves the device. Marginalia declares two:

• Website content. A highlight contains the passage you highlighted, which is text from the document. The built-in PDF viewer reads the contents of the PDF file you open in order to display and annotate it.
• Web history. The address and title of each document or video you annotate are saved so the Library can list your notebooks and reopen them. This covers only the items you chose to annotate — not the pages you browse.

Both are stored only on your device, and only because the extension cannot show your notes again without them.

What Marginalia does not collect

Marginalia does not collect your browsing history, personal information, location, credentials, form data, keystrokes, or usage analytics. It contains no advertising and no third-party trackers. On an ordinary web page its only action is to find the video element and read or set its playback position, so notes can be pinned to a moment and jump back to it.

Site access

Marginalia asks for no site access when you install it. It requests access only when you ask it to do something that needs it, and at the smallest scope that works:

• Clicking the toolbar icon lets it look at that one tab, for that visit, to find a video or notice a PDF.
• Opening a PDF in the annotatable viewer asks for access to that one site, because the viewer has to read the PDF file to display it.
• Access to all sites is requested only if you switch on "Open PDFs in Marginalia automatically", which needs to recognise PDF links on sites you have not visited yet.

You can withdraw any of this at any time from chrome://extensions. On a page it is granted, Marginalia reads only what it needs — a video's playback position, or the contents of a PDF you chose to open — and transmits nothing.

Limited Use

Marginalia's use of information received from Google APIs adheres to the Chrome Web Store User Data Policy, including the Limited Use requirements.

Your control over your data

• Delete one notebook: open the side panel and choose "Delete this notebook".
• Export: Settings → Download backup writes a JSON file you keep. Individual notebooks export as Markdown.
• Delete everything: removing the extension from chrome://extensions deletes all of its stored data.

Children

Marginalia is a general-purpose tool and is not directed at children. It collects no personal information from anyone, of any age.

Changes to this policy

If this policy changes materially, the updated version will be posted here and the date at the top will change.

Contact

Questions about this policy: zubayar2169@gmail.com, or open an issue on the project repository.