Got an image that’s too large to upload, or too small to print properly? Whether you’re prepping visuals for a blog post, resizing a photo for a job application, or just trying to hit a specific file size limit — GIMP is one of the best free tools to get it done without compromising quality.

In this guide, I’ll walk you through exactly how to resize an image in GIMP — step by step, with screenshots at every stage. The whole process takes under five minutes, even if you’ve never opened GIMP before.

And if you want to go further with GIMP, check out the full GIMP tutorial or learn how to remove an image background and make it transparent in GIMP.

Why Use GIMP to Resize Images?

Fair question — your phone has image resizing apps, and there are plenty of free websites that do the job too. So why bother with GIMP?

The short answer: quality. GIMP is purpose-built photo editing software, similar in capability to Adobe Photoshop but completely free. When you resize an image through a random online tool or a basic mobile app, the algorithm doing the resizing is often unsophisticated — you’ll frequently notice artefacts, blurring, or colour degradation, especially when enlarging.

GIMP uses professional-grade interpolation algorithms (like Cubic and Sinc/Lanczos) to intelligently reconstruct pixel data when scaling — which means your output looks clean and sharp rather than like it’s been through a blender.

It’s also completely free, cross-platform (Windows, Mac, Linux), and capable of far more than just resizing. Once you’re familiar with it, you’ll reach for it for almost every image editing task.

How to Resize an Image in GIMP — Step by Step

Let’s get into it. This method works for any image format — JPG, PNG, WEBP, BMP, you name it.

1. Open GIMP on your PC.

2. Double-click anywhere in the main canvas area. A file picker window will appear — navigate to your image, select it, and click Open.

   

3. Once the image loads, go to the menu bar and click Image → Scale Image…

   

4. A dialog box appears with your image’s current dimensions. Here you can enter your target size in pixels, inches, millimetres, or percentage — whatever unit makes sense for your use case.

   

   Handy tip: By default, GIMP locks the aspect ratio — so if you change the width, the height adjusts automatically to prevent your image from looking stretched or squashed. You’ll see a small chain-link icon between the Width and Height fields. If you want to change them independently (for example, to force a square crop area), click that chain icon to unlink them first.

5. Once you’re happy with the dimensions, click the Scale button. GIMP applies the changes immediately.

   

6. Now to save it — and this is where GIMP trips up a lot of first-timers. Don’t use File → Save, as that saves in GIMP’s native .xcf format. Instead, go to File → Export As…

   

7. In the Export As window, you can rename the file and choose the output format. To change the file type (e.g. save a PNG as a JPG), click Select File Type (By Extension) at the bottom of the window and pick your desired format from the dropdown. Then hit Export.

8. A confirmation window will pop up asking whether you want to overwrite the original file. Click Replace to overwrite, or rename the file first if you want to keep the original untouched — which is generally the safer choice.

   

9. One final Export button click on the next dialog — and you’re done. Your resized image is saved to your PC.

   

That’s the entire process — nine steps that take longer to read than to actually do.

Frequently Asked Questions

Q: How do I resize an image in GIMP without losing quality?
A: When making an image smaller, you generally don’t need to worry — GIMP handles downscaling cleanly and quality is well preserved. When enlarging an image, it’s a different story. Scaling up forces GIMP to invent pixel data that wasn’t there originally, which can introduce blurring if you push it too far. As a rule of thumb, enlarging by up to 20–25% typically looks fine; beyond that, you’ll start to notice softening. If you need a significant upscale, consider using an AI upscaling tool like Upscayl first, then make fine adjustments in GIMP.

Q: Is resizing the same as cropping in GIMP?
A: Not at all, and it’s worth understanding the difference. Resizing (via Scale Image) changes the overall dimensions of the entire image. Cropping cuts away a portion of the image — but the remaining area stays at its original resolution. Crop a large chunk out of a low-resolution image and yes, it can look blurry. They’re two completely different operations serving different purposes.

Q: How do I change the file format when saving my resized image?
A: During the Export As step, look for the Select File Type (By Extension) option at the bottom of the file dialog. Click it to expand a dropdown list of all supported formats — JPG, PNG, WEBP, BMP, TIFF, and more. Select your target format and proceed with the Export.

Q: What if I made a mistake — can I undo the resize?
A: Absolutely. GIMP supports multi-step undo just like any other editor. Hit Ctrl+Z to step back through your changes one at a time, or go to Edit → History to jump to a specific point. Just make sure you haven’t closed the file yet — once exported and closed, the undo history is gone.

Conclusion

Resizing an image in GIMP really is as straightforward as it looks — open, scale, export. The whole thing takes a couple of minutes once you know the steps, and the quality you get out of it beats most online tools hands down.

If you run into any snags following the steps above, drop your question in the comments and I’ll help you sort it out.