Muna privacy policy

Everything Muna reads stays on this device.

Muna is a Chrome extension that lets you find anything you have read in a tab: by matching words, and with smart search, by meaning. This page explains what it stores, where, for how long, what it sends over the network, and how to delete it all.

What Muna stores

For each web page you open, once you allow Muna to read your tabs:

• the page address (URL), title and icon address
• the visible text of the page, up to 200,000 characters
• a fingerprint (hash) of that text, so unchanged pages are not processed twice
• when the page was first read and last seen, and when its last tab closed

For pages you kept on screen for at least 15 seconds, Muna also stores:

• passages: the page's main article text split into pieces of about 1,000 characters, at most 50 per page, each with a fingerprint
• for smart search: a short list of numbers for each passage (384 small whole numbers, one byte each) that describes what the passage is about. The model built into Muna computes them on this device. They are only useful for comparing passages with a search, not for reading.

Pages you only glance at are still found by their words, but are not split into passages.

Muna also stores:

• your settings: whether indexing is paused, your list of excluded sites, how long to keep closed pages, the smart search setting and whether Muna learns from your searches
• what it has learned from your searches, described under "Learning from your searches"
• a count of the requests described under "Network requests", per day and per kind, for the last 7 days. Only numbers: never an address or any page text.
• a list of which open tab shows which page, kept only until you quit Chrome

What Muna never stores

• Pages with a visible password box or a payment card form
• Sites on your excluded list. By default: accounts.google.com, mail.google.com, outlook.live.com and outlook.office.com
• Pages that are not normal web pages, such as browser settings. Muna reads http and https pages, and PDFs (see below).
• Anything in private (incognito) windows. Muna is not allowed to run there.
• Your browsing history, cookies or network traffic. Muna does not ask for those permissions.

Tabs Muna does not read can still be found by their title and address, which Chrome already shows in the tab strip. That title and address are not stored.

Where it is stored

Only in your Chrome profile on this device, in the extension's own storage (IndexedDB and chrome.storage). It is not synced to your Google account and is not sent anywhere.

How long it is kept

When you close the last tab that shows a page, or that tab moves to a different page, the page is kept for 30 days so you can still find it, then deleted with its passages and their numbers. You can choose 7, 30 or 90 days in the options. Pages still open in a tab are never deleted. At most 10,000 pages are kept; past that, the pages closed longest ago are deleted first. When Chrome starts, pages from the previous session count as closed from that moment. If you take back Muna's permission to read sites, all stored page text is deleted at once.

Smart search

Smart search finds pages by meaning, not only by matching words. It is off until you turn it on in the options or on the welcome page.

• The model (all-MiniLM-L6-v2) is built into Muna. Turning smart search on downloads nothing, and it works offline.
• The model runs on this device, in a hidden extension page that starts when it is needed and closes after 5 idle minutes.
• Muna prepares pages for smart search only while you are away from the keyboard, so it never slows you down. It pauses on low battery. Choose "Only when plugged in" to limit it to times your computer is charging. To check the battery it reads whether your computer is charging and the battery level; it does not store them.
• Searching with smart search on turns your search words into numbers on this device. They are not stored or sent.

Learning from your searches

Muna puts the pages you want first by remembering how you used its results. This is on by default and you can turn it off in the options ("Learn from my searches").

• When you open a result, Muna stores the search you typed (in lower case, without a time phrase such as "last week"), which page you opened, where it was in the list, the time, and whether it was found by its words, by meaning or both. It stores the same for each result that was shown above the one you opened, marked as passed over.
• When you choose "Not this" on a result, it stores the same, marked as not wanted. That page is then hidden for that exact search and ranked lower for similar ones. "Undo" deletes the record.
• Only the newest 2,000 of these records are kept. Older ones are deleted as new ones arrive.
• A record is deleted together with its page: when the page expires, when you exclude its site, when you take back permission to read sites, and with "Delete all data".
• Turning "Learn from my searches" off deletes every record at once, and nothing more is recorded. Search then ranks results exactly as it would have without learning.
• Nothing is recorded for a tab Muna does not read (a result found by title only), or when you only browse what you read in a time range without typing a search.

These records stay in the extension's storage on this device like everything else. They are never sent anywhere, and no request is made because of them.

PDFs

Chrome shows PDFs in its own viewer, where Muna cannot read the text on screen. So when you look at a PDF in a tab for 15 seconds, Muna loads that same file once more from the address shown in the tab, with your browser's cookies for that site (as reloading the PDF would), reads its text on this device and stores it like any other page. The text is never sent anywhere. A PDF already stored is not loaded again, and one that could not be read is not tried again until Chrome restarts. It does this only while indexing is not paused, only with your permission to read sites, and never for an excluded site. Files over 50 MB are not read, and only the first 500 pages are. Muna checks inside the tab that it really shows a PDF before loading anything, so a page that failed to load, or a security warning, never causes a request. If the site answers with a redirect (for example to a sign-in page), the download stops there. Every one of these requests is counted in the Privacy report.

PDFs on your own computer (file:// addresses) are read only if you turn on "Allow access to file URLs" for Muna in Chrome's extension settings. Reading one does not use the network.

Network requests

Muna sends no analytics and loads no code from the internet. It does not download its model. Only two kinds of request may ever leave the extension, and Muna refuses any other:

1. PDF re-fetch. A new download of a PDF you already have open, as described under "PDFs". It goes to the site the PDF came from, like reloading the PDF would.
2. Answer request. A question and the matching excerpts of your pages, sent to an answer provider you chose, only after you turn that on. Not in this version.

Every request goes through one gate in the code that checks your settings first and counts the request. Automated tests check that no other part of Muna can make a request, and that a full search session, with smart search on or off, sends nothing outside the extension.

Privacy report

The options page has a Privacy report. It shows how many pages are stored on this device, how many search choices are remembered for learning, how many PDF re-fetches and answer requests Muna sent in the last 7 days, and, whenever no answer provider is on, the line "Page text sent off this device: 0".

How to delete everything

• Open Muna's options (right-click the toolbar icon, then Options) and choose Delete all data.
• Or remove the extension from chrome://extensions. Chrome deletes all of its storage.

To delete only what Muna learned from your searches, turn off Learn from my searches in the options.

To stop Muna reading a single site, open that site, open Muna and choose Never index this site. That also deletes what was stored from it.

Permissions