If you need to change the size of an image, be it the dimensions or the size of the file itself, GIMP is the perfect software to do it. Not only is this photo editing program free, but it can be installed on devices running Windows, macOS, and GNU/Linux. You can use it to change an image's dimensions and file size, as well as crop, rotate, and flip an image.
In this guide, we'll show you how to resize image dimensions and file size in GIMP without reducing its quality or resolution. Additionally, we'll go through the process of resizing a layer, canvas, and selection in GIMP.
How to Resize Image Dimensions in GIMP
Knowing how to resize an image can be very handy when you need to post the same image on various social media. Different platforms have different requirements for the aspect ratio and dimensions of their posts. The trick is to change the dimensions of the photo without cropping it, as this could result in the loss of potentially important elements of the image.
Fortunately, you can use GIMP to resize an image's dimensions, and it will only take you a few moments. It doesn't matter what operating system you use; this process is the same on all. First, you need to download the software and install it on your computer or laptop. After opening GIMP, here's what you need to do next:
- Click on the "File" tab in the upper left corner of the window.
- Go to the "Open" option and select the image you want to resize.
- Click on it and select "Open" in the new window.
Notes: You will be able to see the current dimensions of the image in the second half of the title tab (for example, 800 x 1200 – GIMP).
- Select the "Image" tab from the top menu.
- Choose “Scale Image…” from the drop-down menu. This will open the "Image Scaling" dialog box.
- Under "Image Size", manually change the width and height of the image.
- You can also change the value type by clicking the down arrow next to the "px" tab. It is possible to change the value in percentages, millimeters, centimeters, etc. If you don't need it, we recommend leaving it at pixels.
- Click the "Scale" button when you're done.
If there are no other changes you want to apply to this image, you can save it. You can do this by clicking the "File" tab again and choosing "Export As..." Decide which folder you want to save the edited image to and click the "Export" button.
How to Resize Image Dimensions with Mouse Drag in GIMP
There's an even easier and faster way to resize image dimensions in GIMP, and that's by dragging it with your mouse. This is how it's done:
- Launch GIMP and open a new image.
- Click on the “Unified Transform Tool” icon in the left sidebar. It is the sixth icon in the first row.
- Under 'Constrain (Shift)', make sure 'Scale' is checked.
- Under "From Pivot", check the "Scale" box.
- Click on one of the four squares on either side of the photo to resize it.
- To enlarge the image, drag the square to the edge of the window.
- To reduce the size of the image, drag the square towards the center of the window.
You will be able to see the percentage of pixels at the bottom left of the window. If you want to resize it in a different way, go to the "Reset" button in the "Unified Transformation" window. When you're done, save the changes and export the image to your computer.
How to Resize an Image's File Size in GIMP
GIMP also gives you the ability to change the file size of an image. This can be especially handy when you want to send someone an image, but it's too big to fit in the attachments section. This is how it's done:
- Launch GIMP and import an image.
- Make any necessary changes to the image.
- Select "File" in the upper left corner of the window.
- Choose “Export as…”
- Click on the “Select file type (by extension)” option.
- Select "JPEG Image" and click the "Export" button.
- Choose the quality of the image, which will also determine its size.
- Go to “Export” again.
For any image you edit, the smaller the file size, the lower the quality of the image. You can only change the file size of an image if you export it to JPEG format.
How to Resize a Layer in GIMP
You can also add layers above your image in GIMP. To choose the right dimensions for a layer, follow the steps below:
- Select "Layer" from the top menu.
- Click "New Layer" from the drop-down menu.
- Choose the width and height of the layer.
- Click on the “OK” button.
If you want to resize the dimensions of an existing layer, do the following:
- Right click on the layer and choose "Layer".
- Switch to "Scale Layer".
- Change the width and height of the layer.
- Click on the "Scale" button.
That's all we can say about it. You can add as many layers as you want to your project.
How to Resize Without Losing Quality in GIMP
As mentioned earlier, you can change the file size of an image. However, if you reduce the file size too much, you may lose image quality. There are some things you can do to maintain the original image quality. Follow the steps below to do so:
- Open GIMP and import a new image.
- Go to the “Image” tab and select “Scale image…”.
- Change the width and height of the image.
- Next to "Interpolation", select "Cubic". If you see a “Sinc (lanczos3)” option, you can also select that.
- Select "Scale".
- Go to “File”, then “Export as…”.
- Select the file type and choose "JPEG File" from the drop-down menu.
- Make sure the image quality is set to 100%.
- Choose “Export”.
How to Resize the Canvas to an Image in GIMP
In GIMP, a canvas refers to the visible area of the image. Canvas and layers have the same default sizes. To resize a canvas in GIMP, here's what you need to do:
- Click on the "Image" tab in the top menu.
- Select "Canvas Size" from the drop-down menu.
- Change the width and height of the canvas.
- Choose the "Resize" button.
If you want, you can also resize the layers to fit the canvas in the same place. Just go to "Resize Layers" and choose "All Layers" from the menu.
How to resize a selection in GIMP
To draw a selection in GIMP, you can use a variety of tools – the Free Selection Tool, Rectangle Selection Tool, Ellipse Selection Tool, Fuzzy Selection Tool, foreground selection tool, paths tool, color selection tool, etc. . Here's what you need to do:
- Make a selection of your image. You can do this by clicking on one of the selection tools in the left sidebar.
- Go to "Tools" in the top menu and switch to "Transform Tools".
- Select "Scale".
- Change the width and height.
- Click on the "Scale" button.
Resize all your images with GIMP
GIMP may seem complicated to use at first, but once you get the hang of it, you'll use all of its features to your advantage. You can use GIMP to change the dimensions and file size of an image. You can also use it to resize a layer, canvas, and selection. With many creative options, you will be able to design amazing images.
Have you ever used GIMP to resize an image before? What method did you use to do this? Let us know in the comments section below.