Reduce Image Size in KB

Reduce Image Size in KB is a free browser tool for preparing a photo or signature for an application form. You can set a maximum file size or a range with a minimum and maximum, such as 10–20 KB or 20–50 KB. Optional width and height settings let you work on file size and picture dimensions in the same place.
Start by choosing, dropping or pasting an image. Supported inputs include JPG, PNG, WebP and iPhone HEIC. Enter the limits from the receiving form, then choose whether to keep the original dimensions, allow shrinking when necessary, or specify dimensions in pixels or centimetres. Centimetre settings use a DPI value to calculate the pixel dimensions. Output choices are JPG, PNG and WebP; choose a format your receiving form accepts.
The tool tries compression settings to find an output within the requested maximum. Different formats have different limits. PNG does not offer the same quality adjustment as JPG, and preserving exact dimensions may leave fewer ways to meet a very small target. The Original mode allows shrinking when needed and shows the changed dimensions. Keep original exactly prevents resizing. Review the output rather than assuming every combination of image, dimensions and file size can be satisfied.
For a small JPG that remains below a required minimum, the website describes adding blank comment data inside the file. Image viewers skip that comment data, so it increases the file size without changing the picture or its pixel dimensions. The result reports the added bytes. This is useful for small signature images whose compressed files can otherwise fall below a form's minimum. It does not guarantee acceptance by every receiving service.
The size calculation also addresses different meanings of KB: the maximum uses 1,000 bytes per KB and the minimum uses 1,024. The result shows an exact byte count and both readings. Check the preview, dimensions, format and file size before downloading and submitting the result. Image processing happens in your browser, without uploading the image to a server. Matching technical limits does not replace a form's requirements about the content of the photograph or signature.