Batch-rename files on Mac, Windows, and the command line

Mac (Finder)

1. Select the files.
2. Right-click > Rename.
3. Pick Replace Text, Add Text, or Format (sequential numbering).

Windows (Explorer)

1. Select files and press F2.
2. Type a base name; Explorer appends (1) (2) automatically.
3. For finer control, install PowerToys' PowerRename.

CLI (rename / mv)

# Rename every .jpeg to .jpg (macOS / Linux)
for f in *.jpeg; do mv "$f" "${f%.jpeg}.jpg"; done

# PowerShell: add a zero-padded index
$i = 0
Get-ChildItem *.jpg | ForEach-Object {
  Rename-Item $_ ("photo_{0:d3}.jpg" -f $i); $i++
}

Don't get burned

• Keep a copy of the directory before doing a big rename.
• Pad indices with enough digits (001, 002, ...) to avoid collisions.