How do I accept or reject individual changes in Vim's diff mode?

Explanation

When reviewing differences between files in Vim's built-in diff mode, dp and do let you selectively apply individual hunks without leaving the editor. dp (diff put) pushes the current hunk from your window into the other; do (diff obtain) pulls the hunk from the other window into yours.

How it works

• Open a diff view with :diffsplit filename or launch with vim -d file1 file2
• Navigate between hunks using ]c (next change) and [c (previous change)
• With the cursor on a changed hunk:
  • dp — copies the hunk from the current window into the other window
  • do — copies the hunk from the other window into the current window
• The diff display refreshes automatically after each operation

Example

# Left window (your version)       # Right window (other version)
function greet() {                 function greet() {
    return 'hello';                    return 'hi';    ← hunk
}                                  }

With cursor on the hunk in the left window:

• dp replaces 'hi' in the right window with 'hello'
• do replaces 'hello' in the left window with 'hi'

Tips

• Use ]c / [c to jump between all diff hunks without the mouse
• :diffupdate refreshes the diff highlights if they become stale after edits
• :diffoff exits diff mode and restores a normal window layout
• In a three-way merge, you can use :diffget 2 or :diffget 3 to pull from a specific buffer by number