Markdown Editor Pro

About

Markdown Editor Pro is a Markdown workspace built into Chrome.
Open local files, write with live preview, and manage your notes
— without leaving the browser, without an account, without the cloud.

⚡ GETTING STARTED — READ THIS FIRST
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Markdown Editor Pro uses Chrome's File System Access API to read
and write files directly on your computer. Because of Chrome's
security model, the extension cannot access any files until YOU
click a button to grant permission. The editor will appear blank
until you complete these steps — this is expected behavior, not
a bug.

STEP 1 — Open the editor
  Click the Markdown Editor Pro icon (green page with # symbol)
  in the Chrome toolbar (top-right).
  The editor opens as a full tab.
  ↳ Prefer a side panel? Click the puzzle-piece icon → find
    "Markdown Editor Pro" → click "Open side panel".

STEP 2 — Add a folder
  In the left sidebar, click the "Add Folder" button.
  Chrome will show a system folder picker dialog.
  Select any folder that contains your .md files, then click
  "Select Folder" (Mac) or "Open" (Windows).
  Chrome will ask: "Allow Markdown Editor Pro to view files
  in [folder name]?" → click "View files".
  ↳ Your folder and its files now appear in the sidebar.

STEP 3 — Open a file
  Click any .md file in the sidebar.
  The file loads instantly with live preview.
  ↳ No .md files yet? Open the Save menu (top-left) and click
    "New Draft" (or press Ctrl+N) to write without a folder.

TROUBLESHOOTING
  • Sidebar is empty after adding folder
    → The folder may contain no .md files. Toggle "Show all
      file types" in Settings to see other formats.
  • "Add Folder" button does nothing
    → Click once — the system dialog may appear behind the
      browser window. Check your taskbar or dock.
  • Folder disappears after restarting Chrome
    → Click the folder name and grant permission again.
      This is a Chrome security requirement, not a bug.

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WRITE & EDIT
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• WYSIWYG editor (Notion-style) — floating toolbar, slash
  commands, and inline formatting without remembering syntax
• Source editor (raw Markdown / CodeMirror 6) — full syntax
  highlighting, switch with one click
• Three view modes: Edit (WYSIWYG) / Read (preview) / Source
• Split view per code block — see raw source and rendered
  output side by side for Mermaid diagrams and code
• Auto-save to disk with configurable debounce (500 ms – 5 s)
• Save status indicator on every tab (saving / saved / unsaved)
• Unsaved-changes prompt when closing a modified file
• Conflict detection when a file is edited outside the extension
• Drafts — write without a folder, export to disk when ready
• Light / Dark / System theme

────────────────────────────────────────
READ & PREVIEW
────────────────────────────────────────
• Live preview with full GitHub Flavored Markdown (GFM):
  tables, task lists, strikethrough, autolinks
• Mermaid diagram rendering — flowcharts, sequence diagrams,
  class diagrams, state diagrams, git graphs, and more
• KaTeX math — inline $...$ and block $$...$$
• Syntax highlighting for all major programming languages
• Local image rendering — relative paths resolved from folder
• Document outline panel with scroll-spy and heading jump

────────────────────────────────────────
MANAGE FILES
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• Multi-root workspace — add several folders, manage together
• File tree with lazy-loading subfolders
• Inline rename, duplicate, create, and delete files
• Quick file search by name (Ctrl+P / ⌘P)
• Recent files and command palette (Ctrl+Shift+P / ⌘⇧P)
• Workspace and open tabs persist after restarting Chrome

────────────────────────────────────────
EXPORT & SHARE
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• Copy as Markdown — whole file or current selection
• Copy as Rich Text — paste into Word, Google Docs, or Notion
  with formatting intact
• Export to PDF — via Chrome's print API
• Export to HTML — self-contained file with embedded images

────────────────────────────────────────
OPEN MARKDOWN FROM ANYWHERE
────────────────────────────────────────
All sources open inside the same editor for reading or editing:
• Local folders on your computer (via File System Access API)
• Any raw .md URL — paste a GitHub or web link, preview
  instantly in a read-only tab with "Save to Workspace" option
• GitHub repo docs — bulk-save a public repo's Markdown files
  to your local workspace in one click
• Web pages and AI conversations — a floating button appears
  on every page you browse, letting you save any webpage or
  Claude / ChatGPT / Gemini / Perplexity conversation as a
  clean Markdown file

────────────────────────────────────────
SEARCH YOUR NOTES
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• Quick file search by filename (Ctrl+P / ⌘P)
• Semantic search (Ctrl+Shift+F / ⌘⇧F) — find notes by
  meaning, not just keywords, using an on-device embedding
  model (no data sent to any server)

────────────────────────────────────────
PRIVACY
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Your files stay on your computer via the File System Access
API. No account required. No cloud sync. No tracking.