Notepad3 is a lightweight text editor with the many features: code folding, bracket matching, automatic indentation, word auto-completion, convert character encoding between various formats (ASCII, UTF-8, and UTF-16), newline format conversion (between DOS (CR/LF), Unix (LF), and Macintosh (CR) formats), multiple undo or redo, bookmarks, and regular expression-based find and replace. Multi-language, dark mode and color preview many features have been added. Custom 
grepWin is also bundled.
Although the Windows operating system was updated significantly over the past years. However, the default Windows 
Notepad has very simply features since the 1980s. If you need a text editor for simple programming tasks, using the vanilla Windows Notepad just does not cut it. Enter Notepad3! Scintilla-based 
Notepad2, its successor 
Notepad2-mod, its successor Notepad3.
Therefore, we created Notepad3 with all the features that the default Windows Notepad currently lacks. Notepad3 is a fast and light-weight Scintilla-based text editor with syntax highlighting. It has a small memory footprint, but is powerful enough to handle most programming jobs.
Previously we mentioned that Notepad3 can handle almost any programming job and we are not lying. Just take a look at the list of supported programming languages below and spot your favorite.
Syntax highlighting support for over 50 languages: ASP, assembly language, AutoHotkey, AutoIt3, AviSynth, Bash, BAT, C, C++, C#, CMake, CoffeeScript, Common Gateway Interface (CGI), Cascading Style Sheets (CSS), DIFF, HTML, INF, INI, Inno Setup, Java, JavaScript, LaTeX, Lua, Markdown, NSIS, Pascal, Perl, PHP, Python, REG, Ruby, SQL, Tcl, Visual Basic (VB), VBScript, VHDL scripts, XHTML, XML, YAML, D Source Script, Go Source Script, JSON, Makefiles, MATLAB, Nim Source Code, Power Shell Script, Resource Script, Shell Script, R, S, S-Plus, Kotlin, Windows Registry files, configuration files, and improved support for NFO ANSI art.
POX added Notepad3 as alternative to Notepad.js
POX added Notepad3 as alternative to Apimac Notepad
Comments and Reviews
It's so fantastic, Fast & Fast
With around 6000 lines it hangs the system. Can't search and replace.
No Linux support No auto save
The successor to Notepad2-mod in 2023, which has not been updated since 2017
Supports RTL languages and R/S script syntax highlighting out of the box
I used Notepad3 before without any problems. Now it shows Swedish chars with the wrong encoding. I have Googled and tried some solutions suggested but haven't had any luck. I'm now using Notepad++ instead.
I'm not a programmer and I don't need a huge number of functions in Notepad++, there are very complex settings and confusing plugins, but I need a simple and light editor. Notepad3 worked very well for me. I would like to have added tabs, otherwise perfect.