How to resize an image to exact dimensions
How to change an image to a specific width and height while keeping the task requirement in view.
Know whether the requirement is pixels or physical size
Many websites and forms specify pixel dimensions such as 600 × 600 px. Others describe a physical size such as centimetres or millimetres. These are not interchangeable unless the required DPI or other conversion rule is known.
Keep the shape when the requirement allows it
If the target dimensions have a different aspect ratio from your original image, forcing both numbers can stretch the subject. Crop first when the task allows it, then resize to the final dimensions.
Verify the output
Open the processed file or use the result details to confirm the actual width and height. For an application, compare those values with the official instructions before submission.
Privacy note: Where the tool says processing happens in your browser, the selected file is processed locally and is not uploaded by that tool.