This article explains common messages and issues you may see while using Image Resizer.
This file format is not supported
The file you added is not one of the supported image formats.
Supported formats are PNG, JPG, JPEG, TIFF, TIF, GIF, BMP, and JP2.
The image could not be opened
The file has a supported extension, but macOS could not read it as an image.
Try opening the image in Preview. If Preview cannot open it, the file may be damaged or may not be a valid image file.
Enter a width and height greater than zero
This appears when the width or height field is empty, zero, negative, or not a valid number.
Enter whole-number pixel values, such as 800 and 600.
Enter a resize ratio greater than zero
This appears in Bulk mode when Ratio is selected and the ratio is empty, zero, negative, or not a valid number.
Use values such as:
0.5for half size1for original size2for double size
The resized image could not be created
The app could not create the resized image. This may happen if the requested size is extremely large or your Mac does not have enough available memory.
Try a smaller width, height, or ratio.
The resized image could not be encoded
The app could not convert the resized image into the selected output format.
Try a different source image or save the image in another supported format first.
The resized image could not be saved
The app could not write the resized image to the selected location.
Check that:
- You have permission to save to the selected folder.
- The destination drive is connected and writable.
- There is enough free disk space.
- The destination file is not locked or in use by another app.
Bulk resize finished with failures
If Bulk mode finishes with one or more failures, check the status shown on each image row. Files may fail if they cannot be opened, resized, encoded, or saved.