Command line and power tools

Batch file conversion

Updated 2026-07-31 · 4 min read

macOS ships a capable image converter and can drive the rest — no upload sites needed.

Images: sips is built in

sips -s format jpeg *.png --out converted/          # png → jpeg
sips -Z 2000 *.jpg                                  # resize longest side to 2000px
sips -s format heic image.jpg --out image.heic
sips -r 90 photo.jpg                                # rotate 90°

sips needs no install and handles the common web/print conversions.

Whole folder to JPEG at reduced size:

mkdir web
for f in *.png; do sips -s format jpeg -Z 1600 "$f" --out "web/${f%.png}.jpg"; done

Audio and video: ffmpeg

brew install ffmpeg
ffmpeg -i input.mov -vcodec h264 output.mp4          # transcode
ffmpeg -i input.wav output.mp3                       # audio format
ffmpeg -i input.mp4 -vn audio.m4a                    # extract audio
for f in *.wav; do ffmpeg -i "$f" "${f%.wav}.mp3"; done

Documents

# Any printable → PDF via the print system is manual, but:
textutil -convert pdf *.rtf          # rtf → pdf, built in
textutil -convert html document.doc  # doc → html
sips -s format pdf image.jpg --out image.pdf

textutil handles rich text and Word formats without opening an app.

Drag-and-drop conversion

Wrap any of these in a Shortcuts Quick Action (or Automator), exposed in Finder's right-click menu. Then converting is: select files → right-click → your action. The shortcuts-app article covers building one.

The web-upload trap

Converting sensitive documents by uploading to a random online converter hands a stranger your file. Everything above runs locally — no upload, no privacy question, and faster once set up.

Common questions

How do I convert PNG to JPEG in bulk on a Mac?

sips -s format jpeg *.png --out folder/ — sips is built in and needs no install.

What is the best tool for batch video conversion on Mac?

ffmpeg (via Homebrew) — scriptable over whole folders and far more capable than any GUI converter.