A small tool for photo upload limits

SizeKit helps you prepare a photo when a website asks for particular pixel dimensions and a maximum file size.

Who made SizeKit?

SizeKit was created by Haris Asif. Its focus is a practical task: resizing and compressing a photo in one place, with a preview before you save the result.

How the tool works

When you select a file, the image is opened and processed by your browser. SizeKit draws it at your chosen dimensions, then adjusts the JPG or WebP encoding quality to fit the maximum file size. If it cannot fit, it shows an error instead of changing your dimensions without asking.

The tool does not send the photo you select to an image-processing server or save it in an online account. The website itself is delivered by Cloudflare; loading its pages still involves ordinary network requests. The built-in sample image is fetched from the website when you choose it.

Limits worth knowing

• Inputs: JPG, PNG or WebP, up to 20 MB and 40 megapixels.
• Outputs: JPG or WebP, from 1 to 4096 pixels per side.
• The KB setting is a maximum, using 1 KB = 1,000 bytes. It does not enforce a minimum size.
• No cropping, background removal, HEIC support, PDF conversion or PNG output.
• Compression can reduce quality. The tool cannot certify compliance with official photo rules.

Check the final file

Preview and download your result before closing the page. Compare it against the destination’s instructions, including minimum file size and accepted format. Keep your original photo so you can try different settings without repeatedly compressing the same copy.

For practical walkthroughs, read the photo size guides.