Privacy policy

Effective date: 2026-09-10

What this extension does

Markdown Companion renders .md, .markdown, .mdown, .mkd and .mdx files — opened locally via file://, and optionally over http(s) if you turn that on in the options — as styled, readable pages inside your browser, with a folder sidebar listing other markdown files in the same local folder.

Data collection (the extension)

This extension does not collect, transmit, or store any data outside your own device. Specifically:

• It does not use any remote server, analytics, or telemetry.
• All markdown parsing and rendering happens locally, inside your browser.
• The only data it reads is the content of markdown files you open, and — for the folder sidebar — a listing of the folder that file is in.
• Reader preferences (theme, high-contrast mode, font, font size, line height, reading width, sidebar and outline visibility, auto-reload settings, whether to show the word count, and whether to render markdown on websites) are stored locally via chrome.storage.local and never leave your device.

Permissions and why they're requested

Permission	Why
storage	Save your reader preferences locally.
file:///*	Render local markdown files and list sibling files in the same folder for the navigation sidebar. The browser additionally requires you to explicitly enable "Allow access to file URLs" for this extension in chrome://extensions (Edge: edge://extensions) — this permission alone does not grant file access; it only takes effect once you turn that toggle on.
scripting	Used for one thing: reading the same-folder file listing for the sidebar. A file:// folder listing can't be fetched directly, so the extension's background worker briefly opens the folder in an inactive tab, reads the listing, and closes it. No script is injected into any page outside the local folder you are already browsing.
*://*/* (optional)	Off by default. Requested only if you turn on "Also render markdown files on websites" in the options — the browser asks you to grant it at that moment, and you can revoke it there at any time. Once granted, the extension activates only on URLs ending in a markdown extension and ignores every other page. Nothing about your browsing is recorded either way.

Third-party code

Rendering uses open-source libraries bundled into the extension at build time. None of them phone home.

This website

Separately from the extension, markdowncompanion.app uses Cloudflare Web Analytics to count page views. This affects the website only — the extension itself contains no analytics of any kind and never contacts a server.

The website analytics set no cookies, store nothing in your browser, and do not fingerprint you or follow you across sites. Repeat visits are not linked together: Cloudflare counts a "visit" as a page view whose referrer is a different website. Recorded per page view are the page address, the referring page, your country, browser, operating system and device type, and the page load timings measured by the browser's Performance API. Cloudflare states that Web Analytics "does not collect or use your visitors' personal data". We see aggregate counts only, and cannot identify an individual visitor. Cloudflare also processes connection metadata (such as IP addresses) as the site's host; see Cloudflare's privacy policy.

Changes to this policy

Any material change will be reflected in this document with an updated effective date.

Contact

Questions about this policy: support@tarnbeck.com