Compress an image to 100 KB

Plenty of forms, portals and email systems ask for an image under 100 KB. This tool has no “target size” mode, so you get there in a few quick passes: compress, read the size it reports, nudge one setting, and run it again. It takes about a minute, and the image never leaves your browser.

Open the image compressor

Step by step

Open the compressor and add your JPG, PNG or WebP image.
Leave quality at the default 75% and type 1200 in the “Max width/height (px)” box. This scales the longest side down and keeps the proportions.
Press Compress and look at the after size shown next to the image.
Still over 100 KB? Lower the quality to 60% or the max size to 1000 px, then press Compress again. Each run starts from your original file, so repeated tries do not stack up quality loss.
Comfortably under 100 KB? Raise the quality or the max size a notch to keep as much detail as you can, then download.

Resize first, then lower the quality

File size follows pixel count. A phone photo is often 4000 pixels or more on its longest side, and halving both width and height leaves a quarter of the pixels. That is why the max width/height box is usually the bigger lever. Quality helps too, but very low settings produce blocky patches and smeared detail, so trim the dimensions first and use quality for the final nudge.

Sensible starting points: 1200 px at 75% for a general photo, or 800 px at 70% for a profile picture or ID photo that will only be viewed small. Check the form’s stated limit and dimensions before you start.

If your image is a PNG

PNG is lossless, so the quality slider does nothing to it; only resizing makes it smaller. Screenshots and flat graphics often fit under 100 KB just by reducing the max size. A photo saved as PNG is another story: it is usually much larger than the same photo as a JPG. Converting between formats is part of Pro ($9 one-time, no subscription), and transparent areas turn white when a PNG becomes a JPG.

When it will not go under 100 KB

If you see “already optimal”, the result would have been larger than your original, so you got the original back. Set a smaller max width or height and try again.
Images are never enlarged, so a max size bigger than the image changes nothing.
Very detailed photos, such as foliage, crowds or fine texture, compress less than simple ones and need a smaller max size.
The free plan caps quality at 80% and output at 2000 px, which is no obstacle here because you will be well below both.

Compress an image to 100 KB now