Markdown Viewer — Open and Read MD Files Online

A free MD viewer that runs in your browser: open a .md file and read it the way it was meant to look — headings, tables, code blocks, diagrams and math rendered instantly. Works on Windows, Mac, Linux and phones, with no install and no account, and the file never leaves your device.

Open a Markdown file

Free · no sign-up · runs in your browser, nothing is uploaded

Reading mode with the outline sidebar, Claude theme and serif typography — Reading mode with the document outline, here in the Claude theme with serif body text.

How to open an MD file online

An .md file is plain text written in Markdown, so any text editor can show its source — but the source is not what you want to read. Drop the file onto this page (or use Open → Open file) and the viewer renders it as a formatted document: # becomes a heading, **text** becomes bold, pipes become a real table. Paste text straight from a chat or a repo, or point the viewer at a raw URL; GitHub blob links are converted to the raw file automatically.

Documents you open are kept in your browser's local storage so they are still there when you come back, and you can switch to Preview mode for a clean, distraction-free reading view with an outline sidebar.

An MD viewer for Windows, Mac and Linux — nothing to install

Markdown files have no built-in viewer on most computers: double-clicking one usually opens a text editor with the raw symbols. Native Markdown apps fix that, but they are a download per computer and a separate app per operating system. This viewer is a web page: the same one works in Safari or Chrome on a Mac, Edge or Firefox on Windows, any browser on Linux, and on iPhone and Android. Not sure what an .md file is or how to open one? The MD file guide walks through it system by system.

A viewer that renders everything

Most online MD viewers stop at basic formatting. This one renders the full GitHub-Flavored Markdown set plus the extensions technical documents rely on: fenced code with syntax highlighting for 50+ languages and a copy button, GitHub-style alerts (> [!NOTE]), task lists, footnotes, collapsible <details> sections, YAML front matter, Mermaid flowcharts and sequence diagrams, and KaTeX math. Inline HTML is sanitized before it reaches the page, so untrusted files are safe to open.

Read AI-generated Markdown properly

ChatGPT, Claude and coding agents answer in Markdown, and copying that into a notes app leaves you with stray asterisks and broken tables. Paste the answer here instead: the tables, code blocks, math and Mermaid diagrams render exactly as intended, and Export → Download .html or Print / Save as PDF turns it into something you can send on. Working with files such as CLAUDE.md, AGENTS.md or SKILL.md? See the CLAUDE.md viewer; for diagrams, the Mermaid live editor.

See it in action

Syntax-highlighted TypeScript, Python, Bash and diff code blocks with language labels and copy buttons — Code blocks get a language label, syntax highlighting for 50+ languages and a copy button — this is the One Dark theme.

KaTeX display math and a Mermaid flowchart rendered inside the preview — KaTeX formulas and Mermaid flowcharts render right inside the document.

GitHub-style Note, Important, Warning and Caution alerts, a quote and a collapsible details section in the GitHub Dark theme — GitHub-style alerts, blockquotes and collapsible <details> sections, in GitHub Dark.

The theme picker showing 16 light and dark themes with colour swatches — Sixteen themes, each with its own syntax palette — or follow the system light/dark setting.

Markdown Viewer on a phone in reading mode with the bottom action bar — On phones the viewer becomes a single-pane reader with a bottom bar for Edit, Read, Outline and More.

How it works

1
Open a .md file — drag it onto the page, pick it from disk, paste the text, or enter a URL.
2
Read it rendered. Use the outline to jump between headings and pick one of 16 light or dark themes.
3
Keep it, share it as a link, or export it as HTML or PDF. The file stays on your device.

What you get

Opens .md, .markdown and .txt

Drag and drop, file picker, paste, or a URL (GitHub and Gist links work).

GitHub-flavored rendering

Tables, task lists, strikethrough, autolinks, footnotes, alerts and heading anchors.

Code, diagrams and math

Syntax highlighting for 50+ languages, Mermaid diagrams and KaTeX formulas.

Reading mode and outline

Hide the editor, follow the document outline, choose font, size and page width.

16 themes

GitHub Light and Dark, Claude, Paper, Solarized, Nord, Dracula, Catppuccin and more.

Private by design

Everything renders in your browser. Files are never uploaded to a server.

Frequently asked questions

How do I open a .md file?

Drop the file anywhere on the viewer page, or click Open → Open file. You can also paste the Markdown text or open a URL that points to a raw .md file.

Is this Markdown viewer free?

Yes. There is no sign-up, no plan and no watermark. The viewer runs entirely in your browser.

Are my files uploaded anywhere?

No. Files you open are read by your browser and stored only in its local storage. The only server request is the optional "Open from URL" fetch, which is not stored or logged.

Does it support Mermaid diagrams and LaTeX math?

Yes. Fenced ```mermaid blocks are drawn as diagrams and $…$ / $$…$$ formulas are rendered with KaTeX.

Can I use it on my phone?

Yes. On phones the viewer switches to a single-pane layout with a bottom bar for Edit, Read, Outline and More.

Is there a Markdown viewer for Mac and Windows without installing anything?

This one. It runs in any modern browser — Safari, Chrome, Edge or Firefox on a Mac or PC — so there is no app to download. Open the page, drop the .md file onto it and read it rendered.

Can I edit the file too?

Yes — switch to Split or Editor layout. The editor has a formatting toolbar, shortcuts, list continuation and line-accurate scroll sync with the preview.

Related tools

Ready when you are

Paste Markdown, drop a file, or open a URL — the preview appears instantly and everything stays on your device.

Open Markdown Viewer