Why Are GIMP Files So Big? [4 Reasons]

Why Are GIMP Files So Big?

When using an image editor like GIMP, you expect the application to take up some RAM on your hard drive. With any application, there are ways to reduce the amount of memory used by limiting the application’s use of resources. Unfortunately, there are other ways for GIMP to take up space on your hard drive, and that is through large file sizes.

GIMP files are so big for numerous reasons, starting with the fact that GIMP is a raster image editor, so when it opens a file it will expand the image to its full size. Other factors that contribute to large file sizes are as follows:

  1. XCF File Format
  2. Amount of Layers
  3. Additional Images
  4. Canvas Size

There are explanations and workarounds for each of these elements. Fortunately, there are ways to reduce file size, and included in this article are suggestions for each element.

4 Reasons GIMP Files Are So Big

Opening a compressed file and seeing the image expand to its full size isn’t a cause for concern. Once the project is underway, the more you add to it, the more likely it is for the file to grow in size. Your design process is where you will look for ways to reduce your file size. How you save your file will also determine how much space the file takes on your hard drive.

Large file sizes are a challenge you will face in other design applications, like Photoshop, but you can use one of the workarounds laid out in this article or use a different program or website like Placeit.net to make designs with smaller file sizes.

1. XCF File Format

GIMP’s native file format is XCF, an uncompressed file size. Compression reduces the size of the image file by removing unnecessary bits of metadata from the image file. This reduction may slightly affect the image quality, especially if the file is edited and saved more than once. When a file is uncompressed, it maintains every piece of metadata, so the image quality is protected, but the file size is larger.

If you don’t mind a slight loss in image quality, you can opt for saving your file in another file format that uses lossy compression, which will reduce the amount of space the file takes up in your storage. GIMP supports many other file formats, including BMP, PDF, PNG, SVG, and many others.

2. Amount of Layers

The rule of thumb for file size is the more you add, the larger the file. One of the areas that can greatly affect the size of your file is the number of layers in your image. Be mindful and intentional when adding layers to your image, and try to cut any unnecessary layers where you can.

Depending on the nature of your project, the number of layers can’t always be helped, especially if the project is work-related. If that is the case, there are other ways to reduce the size of your file.

3. Amount of Images

Another area that can add up and cause large file sizes is added images. It isn’t just the amount of images, but the type of image and its size. Multiple images, pixel dimensions, and linked images versus embedded images will affect the overall file size.

The only way to combat these factors is to use fewer images, smaller pixel dimensions, and linked images instead of embedded ones. Again, some of these elements may not be able to be changed or reduced, and you will have to rely on other means of reducing your file size, like a lossy compression file format.

4. Canvas Size

The size of your canvas is dependent on your design. Typically a designer will know what size is needed to accommodate their vision before starting. Applications like Photoshop require canvas sizes to be selected and set before starting the design. The larger the canvas, the larger the file size when you save your design.

To resolve this problem, you can reduce the size of your overall design, export the design at a smaller size or crop out negative space from around your image. Keep in mind that once you scale down, you can’t scale back up without affecting the resolution of your image.


The greatest help to file size is whether or not you compress the file when saving it to your computer. There are multiple ways to compress a file, but the easiest option is to save the image as a JPEG or other compressed file format.