Yes — Filemark is a free, MIT-licensed Chrome extension. It runs entirely in your browser with no account, server, or uploads.

How do I open a local markdown file?

Enable 'Allow access to file URLs' for Filemark at chrome://extensions → Details, then open a file:// path to that .md file and it renders in place.

Which browsers does Filemark support?

Chrome and Chromium-based browsers (Edge, Brave, Arc) on desktop. Mobile Chrome works for drag-drop but lacks the File System Access folder picker.

Getting started — Filemark Docs

Getting started

Install, open a file, and (optionally) flip two switches so Filemark can render local and remote files.

1. Install

Add Filemark from the Chrome Web Store. It works in Chrome and Chromium browsers (Edge, Brave, Arc). After installing, the first run opens a short welcome page explaining the two permissions below.

2. Open a file

There are three ways to view a file:

Open the app — click the Filemark toolbar icon to open the standalone viewer, then drag a file in, open a folder, or paste a URL.
Open a local file directly — navigate to a file://…/notes.md in the address bar and Filemark renders it in place (needs the file-URLs permission below).
Open a remote file — visit a raw .md/.json/.csv URL (a raw GitHub or gist link) and Filemark renders it instead of showing plain text (needs the remote permission below).

3. The two optional permissions

Filemark ships locked-down: it asks for nothing until you turn it on. Two switches unlock the in-page rendering modes — see Local & remote files for the full detail.

Allow access to file URLs — lets Filemark render file:// documents you open. Toggle it at chrome://extensions → Filemark → Details → “Allow access to file URLs”.
Remote rendering — lets Filemark render raw files served over https://. Enable it from the Setup button in the toolbar (one click).

Not sure if a permission is on?

The toolbar shows a small amber dot on the Setup (rocket) button when a local or remote gate is still off. Click it to finish setup anytime.

4. Make it yours

Switch theme (light / dark / sepia), font, and content width from the appearance menu; press ⇧F for reading mode. Your preferences persist across reloads — even inside the injected file viewer. More in Reading & themes.

Privacy

Everything runs client-side in your browser. Filemark never uploads your files anywhere — see the privacy page.