How do I enable syntax highlighting in Vim?

Explanation

The :syntax on command enables syntax highlighting in Vim, colorizing your code based on the file type. This makes code dramatically easier to read by visually distinguishing keywords, strings, comments, functions, and other language elements.

How it works

• :syntax on tells Vim to detect the file type and apply syntax highlighting rules
• Vim uses the file extension, shebang line, or modeline to determine the file type
• Highlighting colors are determined by your current colorscheme

Example

Open a Python file and run:

:syntax on

Keywords like def, class, import are highlighted in one color, strings in another, comments in another, and so on. The exact colors depend on your colorscheme.

Making it permanent

Add this to your ~/.vimrc to enable syntax highlighting every time Vim starts:

syntax on

Most modern Vim distributions already have this enabled by default.

Tips

• Use :syntax off to disable syntax highlighting
• Use :set syntax=python to manually set the syntax type if Vim does not detect it correctly
• Use :colorscheme desert (or any other scheme) to change the color theme — see all available schemes with :colorscheme <Tab>
• Use :highlight to view all current highlight groups and their colors
• Use :filetype on alongside syntax on for better file type detection
• If highlighting looks wrong, try :syntax sync fromstart to re-synchronize from the beginning of the file
• Use :set background=dark or :set background=light to tell Vim your terminal background color — this adjusts the colorscheme for better contrast
• For large files, syntax highlighting can slow down scrolling — use :syntax off temporarily if you experience lag