How do I pipe a visual selection through an external shell command and replace it with the output?

Explanation

After making a visual selection and entering the command line with :, Vim automatically inserts the range '<,'> for the selection. Appending !{cmd} pipes the selected lines through the shell command and replaces the selection with the command's stdout. This turns any external tool into an in-editor transformation.

How it works

• '< and '> are marks set automatically for the start and end of the last visual selection
• !{cmd} is the filter operator — it pipes the addressed lines to the command's stdin, and replaces them with stdout
• The visual selection does not need to be active at the time you type the command; the marks persist

Example

Visually select a block of JSON text and format it with jq:

{"name":"Alice","age":30}

Select the line in visual mode, then run:

:'<,'>!jq .

The line is replaced with formatted JSON:

{
  "name": "Alice",
  "age": 30
}

Tips

• Common uses: !sort, !sort -u, !column -t, !python3 -m json.tool, !jq ., !fmt, !par
• !sort on a visual selection sorts only those lines, leaving the rest of the file intact
• Combine with !awk or !sed for complex in-place transformations
• The entire buffer can be filtered with :%!{cmd} — the visual selection variant lets you target specific blocks
• If the command produces an error, Vim shows the error output and does not replace the selection