Skip to main content

A Developer's Notepad for Windows

Syntax highlighting, live Markdown preview with math rendering, encrypted auto-save, and native dark mode - all in a lightweight .NET text editor.

Download Free

What is Notepad#?

Notepad# (NotepadSharp) is a lightweight text editor for Windows built for developers who want more than Notepad but less than a full IDE. Powered by the Scintilla editing engine - the same core behind Notepad++ - it delivers syntax highlighting for 11 languages, a live Markdown preview with math equation rendering, encrypted auto-save with crash recovery, and native dark mode on .NET 10. Whether you are editing a quick config file, reviewing a SQL script, or writing documentation in Markdown, Notepad# stays fast, focused, and out of your way.

Features

Advanced Code Editing

Powerful Editing Engine

Built on the same Scintilla editing component used by Notepad++ and other professional editors. Unlimited undo/redo, automatic bracket matching, code folding, and a full-featured Find & Replace dialog with regex support, case sensitivity, and whole word matching.

  • Unlimited undo/redo
  • Bracket matching and automatic code folding
  • Regex-powered Find & Replace with Go To Line
  • Zoom in/out with Ctrl+Mouse Wheel or keyboard shortcuts
  • Case conversion and date/time insertion

Syntax Highlighting

Syntax Highlighting for 11 Languages

Out-of-the-box highlighting for C#, C/C++, Python, JavaScript, TypeScript, JSON, XML, SQL, PowerShell, Batch, and Markdown. Each language has separate color schemes for light and dark themes. Adding a new language is as simple as dropping a JSON definition file into the SyntaxDefs folder.

  • 11 built-in languages with separate light and dark color schemes
  • Auto-detection by file extension with manual override
  • Extensible via JSON syntax definition files
  • Keyword highlighting, string and comment coloring, operator styles

Markdown Preview

Live Markdown Preview with Math Support

Open any .md file and get an instant rendered preview powered by WebView2 and Markdig. Code blocks are syntax-highlighted via highlight.js, math equations render with KaTeX, and the preview auto-refreshes when the file changes on disk. Right-click to edit in the text editor, copy, print, or save as HTML.

  • Live preview rendered with WebView2 and Markdig
  • Syntax-highlighted code blocks via highlight.js
  • KaTeX math rendering - inline ($...$) and display ($$...$$)
  • Auto-refresh on file changes with scroll position preservation
  • Save as HTML or print directly from the preview

Security & Privacy

Encrypted Auto-Save and Secure Deletion

Never lose work again. Timer-based auto-save protects your files with NTFS EFS encryption. If the application crashes, recover your last auto-saved version instantly. When you need to permanently destroy a document, secure file deletion overwrites the data before removing it. Optional screen capture protection prevents screenshots of sensitive content.

  • Timer-based auto-save with configurable interval
  • NTFS EFS encryption of auto-save files
  • Crash recovery via Tools > Auto-Save > Load Last
  • Secure file deletion (Destroy Document)
  • Optional screen capture protection

Smart File Handling

Encoding Detection and Large File Safeguards

Notepad# auto-detects file encoding.

  • Auto-detection of UTF-8, UTF-16 LE/BE, and ANSI encodings
  • Click-to-change encoding and line ending conversion
  • Drag-and-drop file opening and recent files list

And More

Native Dark Mode

Light, Dark, and System themes. Theme-aware editor colors and markdown CSS adapt automatically.

Printing Support

Page setup with configurable margins, orientation, and paper size. Headers show the filename, footers show page numbers.

Window Customization

Word wrap, line numbers, status bar toggles, always-on-top mode, adjustable semi-transparency (20-100%), and custom per-file window titles.

Command-Line Interface

Open files with --line to jump to a specific line, --encoding to force encoding, --readonly for read-only mode, or --edit to open .md files in the text editor.

.NET 10 Native

Built with the latest .NET 10 for a fast, lightweight, fully native Windows experience with no Electron overhead.

Frequently Asked Questions

Get Notepad# Today

A fast, focused text editor for developers. Free, lightweight, and built for modern Windows.

Download for Windows
v1.4.0 20 MB Windows 10, Windows 11