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Convert PNG to JPG on Mac: 3 Methods

Convert PNG to JPG on Mac with GetCompress, Preview, or sips. Keep PNG when you need transparency; flatten first when you do not.

By Petr Samokhin

The CMS wants JPEG. The portal rejects PNG. You have Figma mockups or Retina screenshots. JPEG is smaller and opens everywhere, but you lose transparency. Flatten on a solid background in your design tool first when alpha mattered in the layout.

PNG vs JPEG

PNGJPEG
TransparencyYesNo (flat background)
File size at same dimensionsOften largerOften smaller
Sharp UI and textExcellentGood at high quality
Best forUI with alpha, logosPhotos, uploads, email

Keep PNG for logos on varied backgrounds, soft shadows on non-white pages, and icons on photos. Convert when the layout already has a solid fill, the image is photo-heavy, or upload limits force a smaller file.

Conversion is lossy even at high quality. Do not convert the same file to JPEG repeatedly. For modern sites, see PNG to WebP on Mac .

Method 1: GetCompress

Best for: Whole folders with max width and quality in one pass.

GetCompress image settings with JPEG output, quality, and max width options
  1. Drop a folder of PNG mockups into GetCompress .
  2. Choose JPEG output.
  3. Set max width (often 1920 px) and quality (for example High or Medium).
  4. Preview a UI screenshot with small text, then export.
  5. Save a preset such as “client JPEG 1920 high” so you can reuse it next time.

Processing stays on your Mac. Image compression uses quality and dimensions, not an exact target file size.

Method 2: Preview

Best for: One or a few files.

  1. Open the PNG in Preview.
  2. Optional: Tools → Adjust Size… to display width.
  3. File → Export… → JPEG, set Quality, save with a new name.

Preview does not batch-convert a folder in one click.

Limitation: Slow for fifty mockups.

Method 3: sips in Terminal

Best for: Scripted folders with no extra install.

mkdir jpg-out
for f in *.png; do
 sips -s format jpeg -s formatOptions 85 "$f" --out "jpg-out/${f%.png}.jpg"
done

Resize and convert:

sips -Z 1920 -s format jpeg -s formatOptions 85 myfile.png --out myfile.jpg

Spot-check one output before you batch fifty files.

Limitation: No preview UI or saved presets.

Which method should you use

SituationStart here
Folder, presets, previewGetCompress
One filePreview
Scriptssips

More image workflows: how to compress images on Mac .

Check before you upload

Zoom to 100% on small text and gradients. Keep masters in png-src/ and write JPEG to jpg-out/. Soft text usually means quality is too low or the source was already lossy.

When Preview alone is enough

Preview can finish a single opaque PNG that already sits near the right width.

GetCompress fits when you often get a folder of mockups that need the same width and quality. It does not replace Figma or Photoshop. Prefer PNG to WebP on Mac when the CMS already serves WebP.

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