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To resize an image for a website or catalog, change its pixel width and height in an editor, then export a separate copy. In GIMP 3, Image → Scale Image changes the number of pixels in the whole image. Changing the editor zoom or only the print resolution does something different. Start with the dimensions and aspect ratio required by the destination.
Check the destination before editing
Find the target width, height, file type, and any upload limit. A website banner, product thumbnail, and social post may each need a different crop. Save the original photograph first so you can create another version later. If the platform specifies a square image but the original is wide, simply entering equal width and height values can distort the subject. Decide what portion to crop or how to add space around it.
Resize in GIMP, step by step
- Open the image and confirm you selected the right source file.
- Choose Image → Scale Image and set the measurement unit to pixels.
- Keep the width and height linked when the original proportion should remain.
- Enter one target dimension and review the calculated other dimension.
- Choose an interpolation option, apply the change, and inspect important details.
- Use File → Export As to save a new file with a clear name.
- Open that exported file outside GIMP and test it at its actual display size.
The GIMP documentation explains that scaling changes the image content and canvas together. For a layered project, check how small layers behave after a substantial reduction. Do not overwrite the editable master just to prepare a smaller web copy.
Use this review table
| Decision | What to check |
|---|---|
| Destination | Required pixel dimensions, aspect ratio, and upload limit |
| Framing | Whether the whole product or subject remains visible |
| Quality | Text, edges, and important details at mobile size |
| Delivery | Exported copy opens correctly; original remains available |
Scaling is different from cropping
Scaling changes the pixel dimensions of the image. Cropping removes part of the visible frame. A rectangular product photo does not become a good square listing image merely because it is forced into square dimensions. That can make a circular object oval or misrepresent the product. Crop deliberately, or place the original in a square canvas with suitable margins. Review the final thumbnail in the actual listing, where interface elements may cover part of the frame.
Enlarging pixels does not restore detail
GIMP notes that an enlarged raster image uses interpolation to calculate new pixels; it does not recover detail missing from the source. A blurry or tiny photograph will not become a sharp high-resolution capture just because the dimensions box shows a larger number. When the source is inadequate, find the original capture or take another photo. An enlarged copy may still be acceptable for a limited use, but judge the actual result instead of the numeric dimensions alone.
Pixel dimensions and print resolution are separate
For web delivery, width and height in pixels directly describe the image grid. A DPI value relates pixels to a physical print size. Changing that setting without resampling does not add pixels for a website. For printed material, ask the printer about the required physical dimensions and file specifications. For a web page, test the image in the layout, including how it behaves on a phone.
Export copies for each use
Name versions by purpose and size, such as a catalog thumbnail and a full product view. Pick a format with the required transparency and compression behavior. After export, inspect file properties and reopen the image. For a batch of catalog photos, finish one representative sample before repeating the settings across all files. This catches an unsuitable crop or quality choice before it affects the entire catalog.
Common questions
Does zooming in GIMP resize the image? No. Zoom changes only how the editor displays it. Use Scale Image to change the exported pixel dimensions.
Can I type any width and height? You can, but unlinking them may distort the subject. Use a crop or canvas adjustment when a different proportion is needed.
Start with the intended display area, resize a copy, and approve the exported file in that destination. The smallest file or largest pixel count is not automatically the right image.
