Compress a PNG to 100 KB
Get a PNG under 100 KB — either losslessly by resizing, or by converting to JPG or WebP when the picture is a photograph rather than a graphic.
- Runs in your browser
- Files are never uploaded
- Free, no account
1 KB = 1024 bytes, the same arithmetic your operating system uses.
Only kicks in when quality 5 still overshoots.
PNG has no quality dial — and that changes everything
JPEG lets you trade fidelity for bytes with a single number. PNG cannot: it is a lossless format, so every pixel comes back exactly as it went in and there is no setting to turn down. The only levers available are how many pixels there are and how many distinct colours they use. That is why, with PNG output selected, this tool binary-searches the scale factor rather than a quality value, and reports the dimensions it settled on.
Is PNG the right format for your image?
| Content | Keep as PNG? | Why |
|---|---|---|
| Screenshot of an interface | Yes | Sharp text and flat panels compress losslessly to very little; JPEG would ring around every letter |
| Logo, icon, line art | Yes | Few colours, hard edges — PNG's ideal case, and alpha is preserved |
| Chart or diagram | Yes | Large flat fills, crisp lines |
| Photograph saved as PNG | No | Often ten times larger than the same picture as a JPEG at indistinguishable quality |
| Photo with transparency | Use WebP | Keeps the alpha channel but compresses the photo lossily |
If your PNG is really a photograph, switch the output format to JPG or WebP in the options. That single change usually takes a 3 MB file under 100 KB without any resizing at all.
Why PNG files get so big
PNG compresses by predicting each pixel from its neighbours and Deflate-compressing the residuals. That is devastatingly effective on flat colour and repeated patterns, and nearly useless on photographic noise, where every pixel differs slightly from its neighbour by design. A camera photo is essentially incompressible to a lossless codec — which is exactly why lossy formats exist.
Getting a real PNG under 100 KB
- Reduce the dimensions. The search does this automatically, halving the area roughly halves the bytes. For a screenshot, exporting at 1× rather than a Retina 2× is often the whole fix.
- Crop the chrome. Screenshots usually include a lot of frame you do not need. Removing it is free bytes and a clearer image.
- Fewer colours help. Gradients, drop shadows and glassy blur effects add thousands of unique colours to what would otherwise be flat regions, and PNG has to encode each transition.
- Check for a hidden photo. A screenshot that includes a photographic hero image is a photo as far as the encoder is concerned.
Transparency
PNG and WebP both carry an alpha channel; JPEG does not. If your image has transparent regions and you switch the output to JPG, those regions become solid — which is almost never what you want for a logo. WebP is the useful middle ground: alpha support plus lossy compression, so a transparent product shot can drop under 100 KB while staying sharp.
What the search shows you
Because there is no quality axis, the attempt table lists scale percentages instead: 100%, then 55%, then 77%, converging on the largest size that still fits. The final row tells you the dimensions you actually got. If those are much smaller than you need, that is the honest signal to change format rather than to keep shrinking.
Local, lossless and unlimited
All resizing uses a Lanczos3 filter and all encoding happens in your browser through a WebAssembly PNG encoder. Nothing is uploaded, there is no per-file cap, and you can iterate as many times as you like — which matters here because finding the right trade-off between dimensions and format usually takes two or three attempts.
Related
Compress a JPEG to 100 KB · PNG to JPG · PNG to WebP · any target you type.
Questions
Why is there no quality slider for PNG?
Because PNG is lossless — there is no quality parameter to search. The only lever is the pixel count, so with PNG output the tool binary-searches the scale factor instead and reports the dimensions it settled on.
My PNG is a photo. What should I do?
Switch the output format to JPG or WebP. PNG stores photographic noise almost verbatim, so a photo saved as PNG is routinely ten times larger than the same picture as a JPEG at indistinguishable quality.
Will I lose transparency?
PNG and WebP keep the alpha channel. JPG has none, so transparent areas become solid — use WebP if you need both a small file and transparency.
Is PNG ever the right choice at 100 KB?
Yes, for screenshots, logos, line art, charts and anything with large flat areas and sharp text. Those compress extremely well losslessly, and JPEG would put visible ringing around every letter edge.