How do I run the same command across all open buffers at once?

Explanation

When you need to apply the same change to every file you have open in Vim, switching to each buffer manually is tedious and error-prone. The :bufdo command iterates over every buffer in your buffer list and executes a given command in each one, making bulk edits fast and reliable.

How it works

• :bufdo {cmd} — execute {cmd} in every listed buffer
• Vim switches to each buffer sequentially, runs the command, then moves to the next
• Combine with | update to save each buffer after the change

A common pattern is :bufdo %s/old/new/ge | update — this replaces old with new in every open buffer and writes each file. The e flag prevents errors when a buffer has no matches.

Example

You have three files open and want to replace all instances of var with const:

:bufdo %s/\<var\>/const/ge | update

This visits each buffer, performs the substitution, and saves:

Buffer 1 (app.js):    var x = 1;   →  const x = 1;
Buffer 2 (utils.js):  var y = 2;   →  const y = 2;
Buffer 3 (test.js):   var z = 3;   →  const z = 3;

Tips

• Use :bufdo with any Ex command — for example, :bufdo set expandtab | retab | update to convert tabs to spaces in all buffers
• :argdo is the equivalent for the argument list, and :windo for visible windows
• Add | update to auto-save, or omit it to review changes before writing
• Use :set hidden if you get errors about unsaved buffers when switching