This independent tutorial covers everyday editing in Notepad++, the free Windows editor from Don Ho and contributors. It assumes the program is already installed from the official downloads page.
Open and save a file
Choose File, then Open, and pick a text or source file. Choose File, then Save, to write it back. Save As stores a new copy. Notepad++ edits the file you opened. It does not compile it.
If the characters look wrong, use the Encoding menu to interpret or convert the file, for example to UTF-8. That menu does not translate the program’s own buttons.
Work in tabs
Each open file has a tab. Click a tab to switch. Close a tab when you are finished with that file; the program stays open. The View menu can move or clone the current document into a second view when you want two files side by side.
Set the highlighting language
Notepad++ usually picks a language from the file extension. When it does not, open the Language menu and choose one, such as Python or HTML. The user manual describes about 90 built-in languages, plus user-defined languages.
Colors are a reading aid. They are not a compiler, a linter, or a runtime. Files larger than 200 MB skip highlighting by default. That limit is under Settings, Preferences, Performance.
Fold a section
Click a fold marker in the left margin to hide a block, such as a function. Use the View menu to fold or unfold the whole file. Folding only changes the display.
Search the open file
Press Ctrl+F or choose Search, then Find. Type the text and use the button your version shows for the next match. The find-and-replace tutorial covers replace, regular expressions, and folder search.
Change the menu language
Menu language and file encoding are different. If the installer included localization files, open Settings, Preferences, General, and choose Localization. The file you are editing keeps its own encoding.
The Macro menu can record a short series of editing commands, play them back, and save the recording. Try a new macro on a copy of the file first. A macro does not build or run a program.