Markdown Viewer

A lightweight Windows-oriented Markdown viewer built with tkinter, tkinterdnd2, and tkhtmlview.

It supports live preview, drag-and-drop opening, recent files, a popup settings panel, and basic text selection/copy interactions.

Features

• Open local .md files from the File menu
• Drag and drop Markdown files into the window
• Auto-reload when the current file changes on disk
• Restore the last opened file on next launch
• Keep up to 5 recent file paths
• Popup settings window for:
  • font size
  • line height
  • window opacity
  • always-on-top
• Markdown support for:
  • headings
  • paragraphs
  • line breaks
  • tables
  • fenced code blocks
  • simple unordered lists
• Text interaction support:
  • select text
  • Ctrl+C copy
  • Ctrl+A select all
  • Esc clear selection
  • double-click to select a word
  • triple-click to select a line
  • right-click context menu

Requirements

• Windows
• Python 3.11 or compatible Python 3 version

Install

Install dependencies in the project directory:

pip install -r requirements.txt

If you want to use a specific Python executable:

& 'C:\Users\ASUS\AppData\Local\Programs\Python\Python311\python.exe' -m pip install -r requirements.txt

Run

python main.py

Or with the explicit Python path:

& 'C:\Users\ASUS\AppData\Local\Programs\Python\Python311\python.exe' main.py

Usage

Open a file

• Click File -> Open File
• Or drag a .md file into the viewer window

Recent files

• Click File -> Recent Files
• The app stores up to 5 recent paths
• The last opened file is restored automatically at startup if it still exists

Settings

Click Settings to open the popup panel and adjust:

• Font Size
• Line Height
• Opacity
• Always On Top

Settings are saved to config.json at runtime.

Keyboard And Mouse Shortcuts

• Ctrl+C: Copy selected text
• Ctrl+A: Select all text
• Esc: Clear selection
• Double-click: Select word
• Triple-click: Select current line
• Right-click: Open context menu

Project Structure

• main.py: main window, file watching, menus, selection and copy behavior
• settings.py: persistent app settings and recent file storage
• theme.py: HTML post-processing for code blocks, lists, and wrapped content
• config.json: saved runtime configuration
• requirements.txt: Python dependencies

Notes

• This project uses tkhtmlview, so some HTML/CSS behavior is intentionally simplified.
• Code blocks and unordered lists are post-processed in Python to improve rendering consistency.
• Recent file paths are stored as plain strings in config.json.