Markdown Editor

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An online Markdown editor powered by editor.md that renders your content in real time as you type. Supports code highlighting, tables, task lists, emoji, LaTeX math, flowcharts, and sequence diagrams, and lets you export the result as Markdown or HTML. The editor language follows the site language automatically

Introduction

The Online Markdown Editor is a visual writing tool built on the open-source editor.md project. It uses a two-pane layout: you write Markdown source on the left while the rendered result updates in real time on the right, giving you a true what-you-see-is-what-you-get experience. There is nothing to install — just open the page and start writing.

The editor ships with a full formatting toolbar that covers undo and redo, bold, italic, all heading levels, blockquotes, ordered and unordered lists, links, images, code blocks, tables, date and time, and emoji. It also deeply supports code highlighting, task lists, a table of contents ([TOC]), LaTeX math formulas, flowcharts, and sequence diagrams, making it well suited for technical docs, study notes, weekly reports, and blog posts. The editor language follows the site's current language automatically, and handy actions such as Copy Markdown, Copy HTML, and a one-click Clear are provided.

Technical Principles

Under the hood, editor.md uses CodeMirror as its source editor, providing code highlighting, bracket matching, line numbers, and autocompletion. The preview is rendered by the marked engine, which parses Markdown into HTML and, together with prettify, highlights code blocks. The editor listens for input events and applies debouncing (300ms by default), refreshing the preview only after you pause typing, which keeps real-time rendering smooth.

For extended syntax, the tool leverages marked extensions to render task lists (- [x]), tables (| col |), and the table of contents ([TOC]). It also integrates KaTeX for LaTeX math, the flowchart library for flow diagrams, and the sequence-diagram library for sequence diagrams. The editor interface is localized through an i18n system: language packs live in the languages directory, and on initialization the correct file is loaded dynamically based on the site's LANG mapping, overriding the defaults so toolbar and dialog text follow the selected language.

Use Cases

  • Technical writing: compose API docs, README files, and code explanations with highlighted code samples
  • Study notes: structure course, book, and meeting content using task lists and an outline
  • Work reports: organize weekly progress and next-week plans with headings, lists, and tables, adding flowcharts to clarify
  • Blogging and content creation: preview the rendered result live, then copy Markdown or HTML to your target platform
  • Math and diagrams: write academic or engineering content with LaTeX formulas and flowcharts, rendered as you type

Frequently Asked Questions

Why is the HTML I copy incomplete?
Copying HTML depends on the live preview output. Make sure preview is enabled; if it is off, the tool automatically turns it on before reading the value, so this rarely happens. If a particular complex element (such as a chart) is not rendered, verify that the matching extension is enabled.
Does the editor support math formulas and flowcharts?
Yes. Wrap LaTeX math in $...$ or $$...$$, use a flow fenced code block for flowcharts, and a sequence block for sequence diagrams. The tex, flowChart, and sequenceDiagram extensions are enabled by default.
Why doesn't the editor language match my site language?
The editor language strictly follows the site's current language, and we ship a dedicated editor.md language pack for all 10 site languages. If a language looks off, it is usually a stale browser cache — force-refresh the page (Ctrl/Cmd + Shift + R) and try again.

Typical Usage

Scenario: Write a weekly work report that includes a code block, a task list, and a table.

  1. Open the Online Markdown Editor and enter the content below on the left
  2. Check the rendered result in the live preview, then click Copy Markdown
  3. Paste it directly into your target document or blog
# Weekly Report

## Completed
- [x] Finished new feature development
- [x] Fixed the login module bug

## Progress Table
| Item | Status | Notes |
| ---- | ------ | ----- |
| Requirements review | Done | - |
| Integration testing | In progress | Due Friday |

## Next Week
1. Finish integration and ship it
2. Write the user guide

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