CreativePro Tip of the Week: Reduce File Size in Photoshop by Cropping or Flattening

This CreativePro Tip of the Week to reduce file size in Photoshop by cropping or flattening was sent to CreativeProse email subscribers on April 5, 2017.

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Need to reduce the file size of a Photoshop document? You may be able to significantly reduce the file size by either cropping or flattening.

If you have a layered file, notice the document sizes in the Status Bar below the image. The two values correspond roughly (sometimes very roughly) to the size of your image as a flattened file (on the left), and as a layered file (on the right).


If you don’t need to preserve the separate layers, flatten the image by choosing either Layer > Flatten Image or Layer > Merge Visible.

If you do need to preserve layers in the file, try cropping the image.

Select the Crop tool and press Return or Enter. You will see a crop overlay fitting the canvas, and any pixels that were outside the canvas will be visible but dimmed.


Press return or Enter again to crop the image to the canvas, discarding any pixels outside that area. The values in the Status Bar will update immediately to reflect the reduced file size.


If just one layer is causing bloated file size, you can crop it and leave the others alone. Target the guilty layer in the Layers panel, and Select All pixels on the canvas (Command/Ctrl+A). Then press Command/Ctrl+J to copy just the selected pixels to a new layer. Then delete the original layer.

Posted on: April 10, 2017

Mike Rankin

Mike is the Editor in Chief of, InDesign Magazine, and He is also the author of several video training series, including Font Management Essential Training, InDesign FX, and InDesign CC: Interactive Document Fundamentals.

1 Comment on CreativePro Tip of the Week: Reduce File Size in Photoshop by Cropping or Flattening

  1. 5 out of 8 images, I saw a larger decrease using this technique rather than using free online tools like kraken. Once you know what you are doing, you can do this technique on the fly.

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