Markdown viewer: open a .md file and read it

A .md file is plain text with markup in it. A viewer turns that markup into headings, tables, task lists and diagrams so you can read the document rather than the syntax. Markbeam does that in the browser, without an account, and without the file leaving your machine.

Opening a file

1. Drag the file onto the window. Drop it anywhere on the page.
2. Or press Ctrl+K and choose Open a Markdown file…, which opens the ordinary file picker.
3. Or paste the text straight into the left pane. Anything you paste renders as you paste it.

The rendered document appears on the right. Press Ctrl+3 for reading view, which hides the editor and gives the rendered page the whole window — the closest thing to a plain reader. Ctrl+1 goes back to the source, Ctrl+2 to the split.

What it renders

• GitHub-Flavored Markdown: tables, task lists, footnotes, strikethrough, autolinks — with a stricter CommonMark mode if you want it.
• Fenced code with syntax highlighting, and ```mermaid fences as rendered diagrams.
• LaTeX maths through KaTeX, > [!NOTE] callouts, ==highlight==, definition lists, and [TOC] for a contents list built from the headings.
• Images embedded in the file, including base64 data URLs.

Where the file goes: nowhere

Reading happens in the page. The file is parsed by JavaScript already running in your browser, and the text is kept in that browser's local storage so it is still there when you come back. There is no upload step and no server copy — you can confirm that in the network panel, which stays silent while you open and read.

Two consequences worth knowing. Clearing site data for this domain deletes the documents, because that storage is the storage. And a document is capped at 1 MiB, which matters only if you paste large images into it.

Reading a long document

• Outline — Ctrl+K → Document outline lists every heading and jumps to it.
• Find — Ctrl+F inside the document, Ctrl+Shift+F across every document you have open.
• Sync scroll — the two panes follow each other, so the source stays beside whatever you are reading.

Taking it further

Once a document is open you can export it as a PDF, present it as slides, copy it as HTML with its table styling intact, or save it to a GitHub or GitLab repository you connect yourself. Everything is in the command palette on Ctrl+K.