Compress an image to a target size

For forms with a size limit

Job portals, visa applications, exam registrations and school systems often say something like maximum 100 KB or maximum 200 KB, sometimes for a photo, sometimes for a scanned signature. A phone photo is usually several megabytes, so it gets rejected. Guessing quality settings by hand takes many attempts; this tool does the searching for you.

How to use it

1. Add your image, or several images.
2. Choose a target: 20, 50, 100, 200, 300 or 500 KB, 1 MB, or a custom value in KB or MB.
3. Pick the output format: JPG (default) or WebP. Stay with JPG unless you know the form accepts WebP.
4. If the form also sets pixel dimensions, enter a maximum width and height.
5. Download the result, or all files as a ZIP. For each file the tool shows the final size, the quality it used and the final dimensions.

Everything runs in your browser; your photo is not uploaded.

How the tool finds the right size

The tool first tries to keep the full dimensions. It tests quality values between 30 and 95 percent using a binary search: it tries the middle of the range, checks whether the file fits, and halves the range again and again until it finds the highest quality that stays under your target. You get the sharpest file that fits, not just any file that fits.

If even the lowest quality is too big, the image has more pixels than the target can hold. The tool then reduces the width and height by 15 percent and searches again, repeating until the file fits. This is why a 20 KB target on a large photo produces a fairly small image: at that size there is simply no room for many pixels.

Getting a better result under a tight limit

• Crop first. Remove everything that is not needed. A profile photo or a signature should not include half the room. Use Crop image before compressing, so the available bytes go to the important part.
• Set the dimensions yourself. If the form asks for something like 600 × 800 px, enter those values as the maximum width and height. Fewer pixels leave more room for quality.
• Start from the original. A screenshot of a photo, or a file that has already been compressed several times, compresses worse and looks worse.
• Aim a little below the limit. The tool counts 1 KB as 1024 bytes. Some websites count 1 KB as 1000 bytes, so their 100 KB means 100,000 bytes, slightly less than the 102,400 bytes the tool allows. If your file is rejected although it seems to fit, set a custom target a few KB lower, such as 95 KB.

Our guide on reducing image file size explains pixels, quality and format in more detail. For passport and ID photos, the passport photo maker gets the proportions right before you compress. Size and dimension rules differ between forms, so always follow the limits written on the form itself.