What this tool is for
Change an image's pixel width and height for a website, profile, presentation, or upload requirement. Enter one dimension to preserve the original proportions automatically, or enter both when you need an exact canvas size.
How to use it
- Choose an image up to 50MB.
- Enter the required width, height, or both in pixels.
- Select Process Image to resize it in the browser.
- Check the result size and download the new image.
What happens to your image
The browser draws the source pixels onto a canvas with the requested dimensions. When only one side is entered, GuavaPix calculates the other from the original aspect ratio. The file remains on your device.
Practical uses
- Create a 1200-pixel-wide image for a blog.
- Reduce a large camera image before adding it to a slide deck.
- Match a profile image to a platform's pixel requirement.
- Generate a smaller preview copy while keeping the original file.
Pixels and aspect ratio
Pixel dimensions describe how many picture elements make up the image. Aspect ratio is the relationship between width and height, such as 4:3 or 16:9. Preserving that relationship prevents faces and objects from looking stretched.
Important limitations
- Upscaling cannot create real detail that is missing from a small source.
- Entering two dimensions with a different ratio can stretch the image.
- Very large output dimensions can exceed mobile-browser memory.
- The exported container can differ from the source depending on browser encoding support.
Frequently asked questions
How do I resize without stretching?
Enter only the width or only the height. GuavaPix calculates the missing dimension using the original ratio.
Does resizing reduce file size?
Usually when you make the pixel dimensions smaller, but the final byte size also depends on image detail and output encoding.
Can I make a small image sharp by enlarging it?
No. Resizing can add pixels through interpolation, but it cannot recover detail that was never captured.
What is the difference between resizing and cropping?
Resizing changes pixel dimensions. Cropping removes outer areas and changes which part of the image remains.