Internally RichEdit follows the lead of Word and the Mac in terminating paragraphs with a CR and converting LF’s and CRLF’s to CR when reading in a file or storing text via an API like WM_SETTEXT or ITextRange2::SetText2. So, a file with LF- terminated lines remains LF terminated and displayed correctly.

To fix this problem, Notepad went one better: it checked to see which line ending came first and then made that line ending the default for the file. I used to open the Unicode Character Data files, which contain LF-terminated lines, with WordPad and save them to convert the LF’s to CRLF’s so that Notepad would display them correctly. For years Notepad didn’t break Unix-convention lines that terminated with a LF (U+000A) instead of a CRLF (U+000D U+000A). The classic Notepad has two handy features that weren’t implemented in RichEdit: line-ending detection (CR, LF, CRLF) and the “Show Unicode control characters” mode (discussed next). This post describes some additions and implementation details. Accordingly, it’s taken significant effort to use RichEdit as the new Notepad’s editing engine.

And classic Notepad has been improved in various ways, such as better performance, line-ending detection (CR, LF, CRLF), and a “Show Unicode control characters” context-menu option. Notepad is often used to view large files, so high performance is important, and lines can be crazy long.

But those plain-text controls have been small and typically exist in dialog boxes. RichEdit has had plain-text controls ever since Office 97 (last century!) and they’ve been used myriad times. You might guess that using a RichEdit plain-text control in Notepad would be a slam dunk. In addition to a Windows 11 look with rounded corners and a dark-theme option, the new Notepad includes several standard RichEdit editing enhancements, such as Alt+x for entering Unicode characters, Ctrl+} for toggling between matching brackets/parentheses, multilevel undo, drag & drop, color emoji, and autoURL detection. The new Windows 11 Notepad uses RichEdit and runs on up-to-date Windows 11 installations.

Notepad++ mac os