Markdown Editor and Previewer

How to use the markdown editor and previewer

1. Type or paste Markdown into the Markdown box. The Preview updates a moment after you stop typing. Use Use a sample to see every kind of formatting at once.
2. Select some text and press a button in the toolbar to format it: bold, italic, strikethrough, heading, link, code, quote, lists and task lists. Pressing the same button again on formatted text removes the marks.
3. To bring in a file, choose or drop a .md or .txt file. To keep your work between visits, tick Keep a draft in this browser. Leave it unticked and nothing is stored.
4. When you are done, use Copy Markdown, Copy HTML, Download .md or Download .html. The downloaded HTML file is a complete page with your formatted text in it.

What Markdown the editor understands

The reader follows the widely used CommonMark rules and adds three extensions that most Markdown tools offer: tables written with pipes, task lists written as dash, space, brackets, and strikethrough written with double tildes.

• Headings with one to six hash signs, or underlined with equals signs or dashes
• Bold with double asterisks or underscores, italic with single ones, and both together
• Bulleted and numbered lists, nested by indenting, with loose or tight spacing
• Block quotes, fenced code blocks with a language name, indented code, and horizontal rules
• Links in the inline form, the reference form, and as plain addresses in angle brackets
• Tables with left, center and right alignment, task lists, and hard line breaks

Safety of the preview

Text you type is never run. Raw HTML such as a script tag is shown as plain text in the preview and is escaped in the HTML you copy. The preview is built with browser calls that create text and elements one at a time, not by pasting HTML into the page, so there is no path for markup in your text to take effect.

Links keep only http, https, mailto and relative addresses. Anything else, such as an address that starts with data: or one meant to run a script, loses its link and shows as plain text. The preview never loads pictures or any other file, so opening a document cannot contact another server. A picture appears as a labeled box with its description.

Using the HTML output

The HTML is plain and unstyled, which makes it easy to paste into a page that already has its own styles. Links get rel attributes that stop the linked page from reaching back to yours. Because pictures become img tags in the copied HTML, check where each picture address points before you publish.

If you need a table to start from, the Markdown table generator builds one from a grid, and the HTML table generator does the same for HTML. To count the words in a draft, use the word counter.

Assumptions and limits

• The reader covers the CommonMark features listed above plus tables, task lists and strikethrough. Footnotes, definition lists, math, emoji short codes, and automatic links for bare web addresses are not supported.
• Raw HTML in the Markdown is never interpreted. If you rely on inline HTML such as a details block, it will appear as text here and in the exported HTML.
• Very long documents are cut at 1,000,000 characters in the preview and in exports, and files over 2 MB are refused.
• A saved draft lives in this browser only. Clearing site data, using a private window, or switching devices means it will not be there.

Formulas reviewed October 10, 2026. See the calculation methodology for how SumPanda rounds, tests and sources its formulas.

Frequently asked questions