How to compress a PNG to 100KB
- Select Choose files, or drop a PNG image on the box.
- The tool aims for under 100KB, which is 102,400 bytes here. It tests quality levels from 95 down to 40 percent and keeps the sharpest result that fits.
- If 40 percent is still too big, it shrinks the width and height by 15 percent at a time until the file fits.
- Select Download. The result ends in
-compressed, so your original is untouched.
Where a 100KB limit comes from
People searching for this usually have a PNG, such as a screenshot, a logo or an exported form scan, that a portal refuses because it is over 100KB. PNG files are lossless, so they are often several hundred kilobytes.
What 100KB means in pixels
100KB is 102,400 bytes, or 819,200 bits. Divide that by the number of pixels and you get the bits each pixel can use. Photos look fine at about 1.5 bits per pixel or more, and the table shows how common sizes fare at 100KB.
| Picture size | Pixels | Bits per pixel | At 100KB |
|---|---|---|---|
| 640×480 | 307,200 | 2.67 | comfortable, the tool keeps all pixels |
| 1024×768 | 786,432 | 1.04 | fine for photos |
| 1600×1200 | 1,920,000 | 0.43 | too tight, the tool shrinks the picture |
| 4000×3000 | 12,000,000 | 0.07 | too tight, the tool shrinks the picture |
At 1.5 bits per pixel, 100KB holds a picture of about 853×640 pixels in a 4:3 shape (545,920 pixels). PNG has no quality dial, so no tool can steer a real PNG to a size target by quality alone. This page therefore saves your PNG as WebP, which can reach 100KB and keeps transparency. A typical screenshot of 1200 pixels across often fits at high quality.
About the output format
Be aware of the output: you give it a PNG and you get a WebP file. If the form insists on a .png upload, WebP will not satisfy it. In that case reduce the pixel size with the image resizer so the PNG itself gets smaller, or ask whether JPG is allowed and use compress JPG to 100KB after PNG to JPG.
Tips
- Screenshots with large flat areas compress best. Photographs saved as PNG shrink the most.
- Check whether the form accepts WebP. Many do not, and then JPG is the safer route.
- Transparent PNGs keep their transparency as WebP. A JPG would turn it white.
- See also: compress JPG to 100KB, PNG to JPG, PNG to WebP, compress to 100KB.
Your images stay on your device. Nothing is uploaded, and there is no sign-up.