Many websites accept photos only below a certain size, and the limit is rarely a round number: 30 KB for a thumbnail, 150 KB for a profile picture, 300 KB for an ID scan. This tool lets you type exactly the size you need in kilobytes and produces an image that is as close to that limit as possible without going over.
Instead of guessing a quality value and trying again, the tool searches for the highest quality that still fits. If the picture is too large even at low quality, it reduces the pixel dimensions step by step, keeping the proportions. Everything happens offline in your browser, so personal photos and documents stay with you.
How to use the Compress Image to KB tool
- Enter your target size in KB, or tap one of the quick sizes.
- Add one or more images by clicking Choose files or dragging them in.
- Pick the output format: JPG works almost everywhere, WebP gives a little more quality per KB.
- Optionally set a maximum width or height if the form also has a pixel limit.
- Check the final size, quality and dimensions, then download each file or all of them as a ZIP.
Why use ToolOrca Compress Image to KB
- Any target size you type, in KB
- Highest quality that still fits
- Automatic downscaling when needed
- JPG or WebP output
- Batch mode with ZIP download
- Private: images never leave your device
How the target size is reached
The tool encodes your image several times with different quality values, using a binary search: it tries the middle quality, then moves up if the file is under the target or down if it is over. After a few rounds it has the best quality that stays below your limit. This is much faster and more accurate than changing the quality by hand.
Some limits are too small for a large photo at any quality. In that case the image is scaled down step by step (keeping its proportions) and searched again until it fits. A 50 KB limit, for example, often means a photo of roughly 600–900 px on the long side.
KB, MB and what forms really mean
This tool treats 1 KB as 1,024 bytes and 1 MB as 1,024 KB, which is how Windows and most upload forms measure files. A few websites use 1,000 bytes per KB; if a file is rejected right at the limit, aim a few kilobytes lower to be safe.
Frequently asked questions
Can I get an image of exactly 100 KB?
The tool aims just under the target, typically within a few percent, because forms reject files that are even one byte over. An exact byte count is not possible with JPG compression.
Why did my image get smaller in pixels?
When the lowest acceptable quality still produces a file above your target, the tool reduces the width and height to make it fit. The proportions are always kept.
What happens to transparent PNG backgrounds?
JPG does not support transparency, so transparent areas are filled with white. Choose WebP if you need to keep transparency.
Is there a size I should not go below?
Below about 10 KB most photos start to look blocky. If you need very small files, crop the picture to the important part first with the Crop Image tool.