Online Markdown Editor Features

This page covers every part of the editor: writing tools, Markdown syntax support, math and diagrams, syntax highlighting, navigation for long documents, tabs, import and export, appearance, and privacy. Each section below answers one specific question.

The editor shows your Markdown source on one side and the rendered page on the other. Scroll one pane and the other follows, since they're locked together. Every change re-renders within about 180 milliseconds, so the preview never feels behind. The source panel behaves like a real code editor, with syntax coloring, line numbers, and smart lists: Enter continues a bullet, a numbered item, or a task checkbox, and Tab indents.

• Cmd/Ctrl+B: bold, Cmd/Ctrl+I: italic, Cmd/Ctrl+K: insert a link
• Shift+Cmd/Ctrl+F or Cmd/Ctrl+H: find and replace, with a match count and replace all
• / or Cmd/Ctrl+F: full-text search over the rendered preview, with matches highlighted

What other writing tools does the editor include?

Drag an image into the editor and it embeds as a data URI, so a document with pictures stays one portable file with no separate assets to track down later. Snapshots save automatically about five seconds after you stop typing, so a bad edit is recoverable even after closing the tab. Open them from History at the top of the app. Thirty automatic snapshots per tab are kept, and you can save the current version yourself at any time, up to twenty, each with a name you can change later. Presentation mode turns the document into slides: three dashes on their own line start a new slide, speaker notes stay visible only to you, and an overview grid lets you jump between slides in full screen.

Markdown Preview renders GitHub Flavored Markdown in full: tables, task lists with live checkboxes, strikethrough, footnotes with backlinks, and emoji shortcodes like :rocket:. Text between double equals signs, like ==this==, highlights. GitHub-style callouts (NOTE, TIP, IMPORTANT, WARNING, CAUTION) render with their icons and colors. YAML frontmatter at the top of a document turns into a compact key and value table instead of showing as raw text.

Does it support LaTeX math?

Yes, through KaTeX. Write inline formulas with single dollar signs, like $x^2 + y^2 = z^2$, and display equations with double dollar signs. Both render instantly as you type, which makes the editor practical for lecture notes, homework, and technical documentation that mixes prose with math.

Can it render Mermaid diagrams?

Yes. A code fence labeled mermaid becomes a rendered flowchart, sequence diagram, class diagram, or Gantt chart. Diagrams follow your light or dark theme automatically, so a Gantt chart built in light mode still reads clearly if you switch to dark mode later.

Code fences get syntax highlighting through highlight.js, covering more than 180 languages, from JavaScript and Python to Rust, SQL, and YAML. Every block shows a language badge in the corner and a one-click copy button, so pulling a snippet out of your notes takes one click instead of a manual selection.

A document outline sidebar tracks every heading from H1 to H4 as you scroll, and a breadcrumb above the page shows exactly where you are. Click any heading to fold its section. Press Cmd or Ctrl plus K to open the command palette, which jumps to any heading or runs any command by name. Images open in a full-screen lightbox gallery, so you can step through a document's pictures one at a time.

Markdown Preview opens documents in tabs, up to 10 at a time, switchable with the keyboard. Everything autosaves to your browser's storage in the background, survives a reload, and syncs across open windows of the app. Your theme, font, text size, and layout preferences persist the same way.

Upload or drag and drop .md, .markdown, and .txt files, or import from any URL. GitHub, GitLab, and Bitbucket links are rewritten to their raw file automatically. A link like /?url=your-file.md opens that file directly, useful for sharing a rendered document without asking anyone to open it themselves. When all 10 tabs are full, the app asks which one to replace instead of silently dropping the new file.

How do I export a Markdown file to PDF?

Print or save a document as a PDF straight from the browser, with the app's own header, sidebar, and editor hidden automatically:

1. Open the Export menu in the header, or press Cmd/Ctrl+K and search for "PDF."
2. Choose "Print / Save as PDF."
3. In your browser's print dialog, pick Save as PDF as the destination.
4. Click Save. The editor, sidebar, and header are hidden automatically, so the PDF is just your document.

Beyond PDF, download the source back as a plain .md file, or export a self-contained HTML file with your current theme, fonts, and column width baked in. Copy as rich text to paste formatted into Gmail, Google Docs, or Slack with headings and bold text intact, or copy just the HTML for a CMS or an email template.

Switch between light and dark themes, and pick from three color-intensity levels for headings and accents: restrained, balanced, or vivid. Five body fonts are available, including a serif (Source Serif 4, the default), a monospace (JetBrains Mono), Inter, Roboto, and Figtree. Text size runs from 13 to 24 pixels, and the page width has four presets, from Narrow to Full. Custom preview CSS is supported too, up to 20,000 characters, saved in your browser alongside your other preferences. Font, size, width and custom CSS all sit in the Aa menu at the top.

Markdown Preview has no accounts and does no server-side document handling. Your Markdown is rendered and stored only in your browser, in IndexedDB and localStorage, so it never reaches a server. Clearing your browser's site data deletes those documents, since there's no server copy to fall back on. The single exception is feedback you choose to type into the in-app feedback form, which is sent to our server because that's what a feedback form is for. Read the full details in the privacy policy.

Most online markdown editors ask for an account before you've typed a single line, because the product depends on syncing your document to their server. Markdown Preview doesn't ask, because there's nothing to sync until you choose to export something yourself.