Notepad4 is a lightweight, native Windows text editor built on the Scintilla editing component and rendered through the Win32 API. It is designed as a direct replacement for the default Windows Notepad, offering a faster, feature-rich editing experience with system-level integration such as Explorer context menu registration, taskbar jump list support, and the ability to intercept system notepad requests.
The editor distinguishes itself with a context-sensitive completion engine that filters suggestions based on preceding punctuation and document content, alongside CPU-optimized encoding detection that leverages SSE2, AVX2, or AVX512 instructions for accelerated text processing. It includes inline color preview calltips that display a color swatch when hovering over hex or 0x color codes, and supports tab-triggered conversion of LaTeX abbreviations and emoji sequences into Unicode characters. The application also provides lexer-driven syntax highlighting with runtime-loaded language definitions, code folding, auto-indentation, and automatic insertion of braces, quotes, and closing markup tags.
Beyond its core editing capabilities, Notepad4 offers Base64 encoding and decoding of selected text, text occurrence highlighting with match counts, and locale-specific behavior adaptation for dialog layouts and keyboard bindings. The project supports multiple compilation methods across Visual Studio, GCC/Clang, Intel Compiler, and LLVM Clang toolchains, with options for CPU instruction optimization and legacy Windows compatibility.
