How to Compress Images on Mac without Quality Loss

2025-12-19
5 min read

How to Compress Images on Mac without Quality Loss

High-resolution photos are beautiful, but they are also massive. A single photo from a modern iPhone can be 5MB to 10MB. If you're trying to upload these to a website or send them via email, you're going to run into problems.

Here are the best ways to compress images on your Mac.

1. Using Preview's "Export" Feature

Preview doesn't have a "Compress" button, but you can control the file size when you export.

  1. Open your image in Preview.
  2. Go to File > Export....
  3. In the dialog box, select JPEG as the format.
  4. You will see a Quality slider. As you move the slider to the left, you'll see the "File Size" estimate change in real-time.
  5. Tip: Usually, 70-80% quality is the "sweet spot" where the file size drops significantly but the image still looks great.

2. The "Modern" Way: imgKonvert (Better Ratios)

The problem with Preview's compression is that it's a bit "dumb" as it just lowers the quality of the whole image. Modern tools use "smart compression" that finds parts of the image that can be simplified without the human eye noticing.

  1. Go to the imgKonvert Image Compressor.
  2. Drag and drop your Mac images.
  3. Our tool uses advanced algorithms to find the perfect balance between size and quality.
  4. Everything happens with maximum privacy and efficiency.
  5. Download your optimized images.

Why Compression is Essential

  • Save iCloud Space: If your iCloud storage is full, compressing your non-essential photos can free up gigabytes.
  • Faster Web Browsing: If you run a website, compressed images are the #1 way to improve your Google PageSpeed score.
  • Email Compatibility: Avoid the "File too large" bounce-back from email servers.

Comparison: Preview vs. imgKonvert

FeaturePreview ExportimgKonvert
Ease of UseBuilt-inEasy to use
Bulk ProcessingPossible but clunkyFast and seamless
Smart AlgorithmNoYes
PrivacyLocalSecure & Private

Summary

For a single file where you just need to "make it smaller," Preview is fine. But for anyone who cares about image quality or needs to process multiple files for professional use, imgKonvert offers a much more sophisticated solution.

Convert Your Images Now

Try our free image converter to quickly transform your images between WebP, PNG, and JPG formats.