About CompressToKB

CompressToKB is a single-purpose tool: compress an image to a target file size. Set a number in kilobytes, drop in a JPG, PNG, or WebP file, and get back the smallest file that still meets it. There's no account, no upload to a server, and no limit on how many times you use it.

It exists because most upload forms, whether a job application, a passport photo service, or an exam portal, give a size limit in kilobytes with no easy way to hit it exactly. General-purpose photo editors make you guess at a quality slider and check the result by hand. This tool searches for the right setting automatically, and tells you honestly if your target genuinely isn't achievable without visible quality loss.

All of the actual compression happens in your browser, using the Canvas API in a background worker thread. Your image is decoded, resized, and re-encoded on your own device. It's never sent anywhere, which is also why the tool keeps working if your connection drops after the page has loaded. See more on how privacy works here.

The site is supported by ads, shown below the tool and never inside it, so compressing an image stays free with no account required. Questions, bug reports, or a format you wish it supported: reach us at hello@compresstokb.com.