How to Resize Images on Mac Without Quality Loss

Step by step

1. 15 sec

   Open your image in Preview

   Locate your image file in Finder. Right-click the file, select Open With, and choose Preview.app.

   Note: Double-clicking usually opens Preview by default.
2. 30 sec

   Open the Adjust Size tool

   In the top menu bar, navigate to Tools and select Adjust Size. Alternatively, click the Markup toolbar icon if visible and select the Resize icon.

   Note: Command + Option + I
3. 1 min

   Input dimensions and resampling settings

   Ensure 'Scale proportionally' is checked to prevent distortion. Verify 'Resample image' is active and choose 'Lanczos' from the dropdown menu to maintain sharpness during scaling.

   Note: Lanczos is the industry standard for high-quality downsampling.
4. 30 sec

   Save the resized image

   Click OK to apply the changes. Navigate to File and select Save to overwrite, or File > Export to create a new file with different settings.

   Note: Always export as a new file if you need to preserve the original master copy.
5. 2 min

   Batch resize multiple images

   Select all files in Finder, right-click, select Quick Actions, then choose Convert Image. Select your format and choose 'Actual Size' or a custom resolution to resize multiple assets simultaneously.

   Note: This is the most efficient method for large batches of photos.