Markdown editor online, with live preview
A free Markdown editor that runs in your browser and renders as you type. Headings, tables, task lists, LaTeX math, code blocks and Mermaid diagrams appear formatted the moment you write or paste them — no install, no split screen, no account needed to start.
Writing and editing are free and need no sign-in · Exports: 1 free without signing in, 2 a day once you sign in
Online Markdown editor
Write in the online Markdown editor right here
This is the Markdown editor itself, not a screenshot. Type Markdown and it turns into formatted text as you go; paste a README, notes or an AI answer and it renders instantly. The sample is a short README with a checklist, a table, a code block, inline and block math and a Mermaid flowchart, so you can try every element before clearing it and writing your own.
How it works
How to use the Markdown editor online
- 01
Write or paste
Start typing Markdown, or press Paste in the toolbar to replace the sample with whatever is on your clipboard. Copy the contents of a .md file, a wiki page or a chat answer — the online Markdown editor reads it as Markdown, not as plain text.
- 02
Edit in the live preview
There is no separate preview pane: the document you edit is the preview. Fix a heading level, add a table row, click a formula to change its LaTeX or open a diagram to edit its Mermaid code, and see the result immediately.
- 03
Take it with you
When the text is ready, copy it out — the clipboard gets Markdown — or use the export buttons in the toolbar to download a Word, PDF or Excel file built from what you see.
What you can do
What this Markdown editor with live preview handles
Markdown shortcuts as you type
Type # and a space for a heading, - for a bullet list, 1. for a numbered list, > for a quote and three backticks for a code block. **Bold** and *italic* turn into formatting as soon as you close them. Ctrl/Cmd + B, I, U and Z work as in any editor, and the toolbar covers the same actions for people who prefer clicking.
Tables without counting pipes
Insert a table from a grid picker, then add or delete rows and columns, toggle the header row and drag column widths from a small table toolbar. Pasted Markdown tables become editable tables too, so you never fix alignment by lining up | characters.
LaTeX math and Mermaid diagrams
Inline $…$ and block $$…$$ math is rendered with KaTeX. Click any formula to edit it in a dialog, or insert a new one from the ∑ button. Mermaid code blocks are drawn as diagrams — flowcharts, sequence diagrams, Gantt charts — and you can reopen the code to change them.
Code blocks and task lists
Fenced code blocks get syntax highlighting for common languages and keep their indentation. Task lists render as real checkboxes you can tick. Blockquotes, links, images and horizontal rules are supported as well, matching what most READMEs and notes use.
Who uses it
When a free Markdown editor in the browser is the right tool
Quick edits on a borrowed or locked-down computer
On a work laptop where you cannot install software, or on a library or school machine, a free Markdown editor in a browser tab is the fastest way to draft a README, a changelog entry or meeting notes and see exactly how they will look.
Cleaning up AI answers before you use them
ChatGPT, Claude, Gemini and DeepSeek reply in Markdown. Paste an answer into the online Markdown editor to read it properly formatted, delete what you do not need, fix a table or a formula, and keep only the parts worth sharing.
Writers and students who are new to Markdown
A Markdown editor with live preview is the easiest way to learn the syntax: type a #, see a heading; type a -, see a list. Nothing to configure, and the toolbar is there when you forget a shortcut.
Technical notes with formulas and diagrams
Lecture notes, design docs and research summaries often mix prose, LaTeX and flowcharts. Writing them in a Markdown editor online that renders math and Mermaid lets you check every formula and diagram while you write, not after.
Comparison
TODOC vs. plain-text editors and desktop Markdown apps
| What you need | TODOC online | Plain-text editor or desktop app |
|---|---|---|
| Setup | Just a browser tab | Download, install, update |
| Preview | Renders as you type | Raw text, or a second pane |
| LaTeX math | Rendered, click to edit | Often needs a plugin |
| Mermaid diagrams | Drawn in place | Raw code or a plugin |
| Tables | Edit cells, add rows | Line up | by hand |
| Word / PDF / Excel file | Export from the toolbar | Extra tools or commands |
FAQ
Markdown editor questions
Is this Markdown editor free?
Yes. Writing and editing are free with no sign-in and no limit. Exporting a file is where limits apply: one free export without an account, then 2 free exports a day after signing in with Google, up to 20,000 characters each. Free exports carry a small TODOC footer; Pro removes it and the limits.
Does it have a split-screen preview?
No — it works the other way round. Instead of raw Markdown on the left and a preview on the right, the text renders where you type it, the way a word processor does. You still write Markdown syntax and get Markdown back when you copy.
Do I need to install anything?
No. The online Markdown editor runs in any modern browser on Windows, macOS, Linux or ChromeOS. The Chrome extension is optional and only needed if you want to export chats directly from ChatGPT, Claude, Gemini or DeepSeek.
Can I open or save a .md file?
There is no file upload or .md download. Open the file in any text editor, copy everything and paste it here. To take your text back out as Markdown, select it in the editor and copy — the clipboard gets Markdown, ready to paste into a .md file.
Is my text saved?
The editor does not store drafts, so keep your own copy of anything important. Your text stays in the browser tab while you edit; it is only sent to TODOC when you click an export button, to build the file.
Which Markdown syntax does it support?
Headings, bold, italic, ordered and unordered lists, task lists, blockquotes, links, images, horizontal rules, inline code and fenced code blocks with highlighting, tables, inline and block LaTeX math and Mermaid diagrams. HTML tags inside Markdown are not rendered.
Can I turn what I write into a Word or PDF file?
Yes. The toolbar has Word, PDF and Excel export. Word files keep heading styles, native tables and editable equations; every table becomes its own Excel sheet. The Markdown to Word and Markdown to PDF pages below explain each format in detail.
Markdown syntax: CommonMark specification · Diagrams: Mermaid documentation
Related
Markdown to Word
Need an editable .docx? Convert Markdown to Word with equations intact.
Markdown to PDF
Turn Markdown into a clean PDF to share or print.
ChatGPT to Excel
Move tables from AI answers into .xlsx worksheets.
Browser extension
Export ChatGPT, Claude, Gemini and DeepSeek chats in one click.
TODOC home
All TODOC tools for AI chats and Markdown in one place.
Start writing in the Markdown editor
Free, in your browser, with a live preview from the first character. Paste your Markdown or start from the sample.
Back to the editor