What Is an Image Resizer?
An image resizer changes the actual dimensions of a photo, either its pixel width and height, its physical size in centimeters or inches, or its overall file size in kilobytes. This tool covers all four ways people typically need to resize an image, since different forms and different situations ask for different units. A passport application might want centimeters, a website upload might want exact pixels, and an exam form might just care about the final file size regardless of dimensions.
Everything happens locally in your browser using the Canvas API built into every modern browser, so your photo never gets uploaded to a server anywhere.
How to Use This Image Resizer
Upload your photo first, either by clicking the upload box or dragging a file onto it. Pick which unit you want to resize by from the dropdown: pixels, centimeters, inches, or a target file size in KB. If you're resizing by pixels, centimeters, or inches, type your desired width and height, and keep Lock Aspect Ratio checked if you want the tool to automatically adjust the second value to match your photo's original proportions. If you're resizing by KB instead, just type your target size and skip the dimension fields entirely. Click Resize Image, then download the result once it's ready.
How It Works
When you resize by pixels, centimeters, or inches, the tool draws your original photo onto a new canvas set to those exact dimensions, using a multi-step downscaling technique for large size reductions so the result stays sharp rather than pixelated. Centimeters and inches get converted to pixels first, using 300 pixels per inch, which is the standard resolution used for print-quality photos. When you resize by target KB instead, the tool searches through different quality levels to find the setting that lands your file size closest to what you asked for.
Why Students Need This Tool
Indian exam and admission forms are inconsistent about which unit they ask for. Some specify pixels, some specify centimeters for a photo that also gets physically printed for ID cards, and some just cap the file size in KB without caring about dimensions at all. Having one tool that switches between all of these units means you don't need three different websites depending on which format your particular form happens to use that year.
Supported Formats
Upload JPG, JPEG, PNG, or WebP files directly. PNG uploads stay as PNG in the result when resizing by dimensions, since PNG preserves transparency and sharp edges better for graphics, while JPG is used automatically when you resize by target KB size, since JPEG's compression is what makes hitting an exact file size possible. If you need to compress an image to one of the common exam presets instead of a custom size, our Image Compressor has quick buttons for 20KB, 50KB, 100KB, and 200KB. For passport-specific sizing with India's exact 3.5cm by 4.5cm standard already built in, try our Passport Photo Maker.