Compress an image to a target size in KB

How to use it

1. Tap Choose a photo and pick the image from your gallery or files.
2. Check the file name, size and dimensions shown, so you know you picked the right photo.
3. Pick a limit, or choose Custom and type a number.
4. Press Compress. The tool tries different quality settings and keeps the best one that fits.
5. Look at the preview, then tap Download JPEG. On Android Chrome the file usually goes to your Downloads folder.

What “KB” means here

This tool uses 1 KB = 1,024 bytes. So 50 KB means at most 51,200 bytes, and 100 KB means at most 102,400 bytes.

Some websites count 1 KB as 1,000 bytes instead. A file of 50,900 bytes is under 50 KB by the first rule but over it by the second. If you are not sure which rule a form uses, choose a custom limit a little lower. For a 50 KB form limit, 48 KB (49,152 bytes) is under both.

A maximum, not an exact size

The result will be at or below your limit, often a few KB below. The tool does not add empty data to make a file exactly 50 KB. Padding a file only makes it bigger without improving the picture. If a form also has a minimum size, check that the result is above it.

Quality and what you give up

JPEG makes files smaller by throwing away detail that is hard to see. A little of that is invisible. A lot of it causes blocky squares, smeared skin and fuzzy text. The tool starts at high quality (92%) and only goes lower when it has to. The result shows the quality it used.

Very small limits on large, detailed photos can be impossible with quality alone. Then you have two honest choices: allow smaller dimensions, or choose a larger limit. A smaller image at decent quality usually looks better than a full-size image at very low quality.

Photos with fine texture, like grass, gravel or low-light noise, need more bytes than plain backgrounds. Cropping away what you do not need gives the tool fewer pixels to store, so it can keep higher quality.

Transparent images

PNG and WebP images can have see-through areas, such as a signature on a transparent background. JPEG cannot store transparency. The tool fills those areas with white, and tells you when your image has any.

Limits and known issues

• Input: JPEG, PNG or WebP only, up to 25 MB, 40 megapixels and 12,000 px on the longest side. Larger images can crash a phone browser, so they are refused with a message.
• Output: always JPEG. If a form needs PNG, this tool is not the right one.
• Photo details stored inside the file, such as camera model, date and location, are not copied into the new JPEG.
• The tool tries at most 40 compressions per run, so it always finishes.
• Animated WebP images are saved as a single still frame.
• It was tested in Chromium on a computer, at phone and desktop widths. It was not tested on every phone or browser.

For help choosing sizes, read image dimensions versus file size or how to reduce photo size on Android.