Change the Screenshot Format on Mac (PNG to JPG, HEIC and More)

Open Terminal and run these two lines. The second restarts the screenshot service so the change takes effect.

defaults write com.apple.screencapture type jpg
killall SystemUIServer

From then on, Cmd + Shift + 3, Cmd + Shift + 4 and the Cmd + Shift + 5 toolbar all save JPG. To go back to the default:

defaults write com.apple.screencapture type png
killall SystemUIServer

Other values people use are pdf, tiff and gif. I tested the matching screencapture -t flag on macOS 27.0.1 and each of jpg, heic, gif, tiff and pdf produced a file. I did not change my own default setting to test the HEIC value through defaults, so try it and confirm the extension on your next screenshot.

Yes. The screencapture command takes a format flag and writes to a path you choose.

screencapture -t jpg ~/Desktop/shot.jpg
screencapture -i -t heic ~/Desktop/shot.heic

-i lets you drag a selection, the same as Cmd + Shift + 4. Without -i it grabs the whole screen. The interactive form is the one to bind to a Shortcuts action or a keyboard shortcut app if you want a second hotkey for JPG.

I built one 2880 x 1800 test screenshot: flat interface colors, thin text-like bars and one noisy photo block. Real screenshots vary a lot, so read this as the shape of the trade-off, not a promise. The PNG was 3,878,872 bytes.

The sizes came from sips and cwebp run on the PNG. The point: PNG is large because it is lossless and Retina screenshots have four times the pixels of a standard display. If size is the problem, read why Mac screenshots are so big and how to shrink them.

Keep PNG for anything with text, code, menus or sharp lines. JPG blurs hard edges, and the damage shows most on small type. Switch to JPG when your screenshots are mostly photos, game footage or web pages with large images, and you share them by email or chat.

Do not use HEIC as a sharing format. Apple devices open it, but a Windows PC or a web upload form often will not. The HEIC not opening on Windows guide covers that failure.

A middle path: leave the default on PNG and convert only the screenshots you send out.

In Preview, open the file, choose File > Export, pick a Format and, for JPG, drag the Quality slider. For a folder, sips does it in one line:

cd ~/Desktop
for f in Screenshot*.png; do sips -s format jpeg -s formatOptions 80 "$f" --out "${f%.png}.jpg"; done

To go the other way and get a PNG from a JPG, use sips -s format png in.jpg --out out.png. Converting a JPG to PNG does not restore detail. It only changes the container, and the file usually gets bigger. More on that in converting JPG to PNG on Mac.

Clipboard route: hold Control while taking the screenshot to copy it instead of saving, then in Preview choose File > New from Clipboard and Export.

For the system setting, Smol is not involved at all. The Terminal command is free and does the job. For converting a handful of screenshots, Preview and sips are enough. See the sips command guide for the options.

Smol earns its $29 when you have a mixed folder of screenshots to shrink, not just re-label. It converts images to JPG, PNG, WebP, AVIF and HEIC in one batch, lives in the Finder right-click menu, and uploads nothing. One caution from Smol’s own limits: converting to JPG ignores the quality setting, so for a small JPG use the compress operation with JPG as the output. By default Smol also resizes images to fit inside 2000 x 2000 pixels, so raise that if you need full Retina size. See the price and details.