Syntax Highlighting - Built-in Languages

Supported Programming Languages

Around 90 Programming Languages are supported by Notepad++:
ActionScript Ada ASN.1 ASP Assembly
AutoIt AviSynth BaanC Batch BlitzBasic
C C# C++ CAML CMake
COBOL CoffeeScript Csound CSS D
Diff Erlang ESCRIPT Forth Fortran fixed form
Fortran free form FreeBasic GDScript Gui4Cli Haskell
Hollywood HTML ini Inno Setup Intel HEX
Internal Search Java JavaScript JavaScript json
json5 JSP KiXtart LaTeX Lisp
Lua Makefile MATLAB MMIXAL mssql
NFO Nim Nncrontab NSIS Objective-C
OScript Pascal Perl PHP PostScript
PowerShell Properties file PureBasic Python R
RC REBOL registry Ruby Rust
S-Record Scheme Shell Smalltalk Spice
SQL Swift TCL Tektronix extended HEX TeX
txt2tags TypeScript Verilog VHDL Visual Basic
Visual Prolog XML YAML

For these languages, Notepad++ supports syntax highlighting (customizable), syntax folding, auto-completion (customizable), function list (customizable via PCRE in xml file).

If your beloved language is not in the list above, you can define it yourself easily, by using the User Defined Languages System. If that doesn’t meet your needs, you could write (or have someone else write) a lexer plugin.

Please note that in Notepad++ v8.3 and newer, Notepad++ has a feature will no longer perform syntax highlighting on files that are over 200MB – this prevents extreme performance slowdown caused by trying to syntax highlight extremely large files. This threshold is configurable in Settings > Preferences > Performance (starting in v8.4.7).

Language Detection Priority

When opening an existing file, Notepad++ has an algorithm for trying to decide which language a given file is, with the following priorities:

  1. A language defined at the command line using -l is applied.
  2. If the file is in the active session file (the automatic session.xml or a manually-controlled session), it will use the language stored in that session.
  3. If the file extension is a “known extension” (whether it’s from the Style Configurator‘s default extension list [in langs.xml or langs.model.xml] or user-defined extension list [from stylers.xml or themes\<ThemeName>.xml] for a built-in language, or the User Defined Language‘s extension settings [from userDefineLang.xml or userDefineLangs\<UDLName>.xml]), Notepad++ will use that language.
  4. If the filename matches one of a few specific names, Notepad++ knows what language they should be:
    filename language
    makefile Makefile
    GNUMakefile Makefile
    CMakeLists.txt CMake
    SConstruct Python
    SConscript Python
    wscript Python
    Rakefile Ruby
    Vagrantfile Ruby
    crontab Shell Script
  5. If the first line in the file gives a known hint as to the file type, it will use that. This includes “prolog lines” starting with <?xml or <?php or <html or <!DOCTPE html or <?, or linux-style “shebang” lines like #!/usr/bin/bash which are looking for sh or python or perl or php or ruby or node to define the correct language.
  6. It will use the default language only if none of the other rules have matched.

As Notepad++ goes through that list in order, it will stop as soon as it finds a matching language for the file. And after Notepad++ has made its detection, you can override what it chose by using the Language menu (and when a session gets saved, the language will remember whatever language is currently active for that file for next time, as described in priority 2).

If you do a Save As on a file, it will use that same sequence for deciding the language, based on the new name and file contents.

Newly-created documents will assume the default language until they are saved.