Image Compressor and Resizer - Nothing Uploaded
Image compressor and resizer
Only affects JPEG and WebP. PNG is lossless, so the slider does nothing there.
| Measure | Before | After |
|---|---|---|
| File size | — | — |
| Dimensions | — | — |
| Format | — | — |
What this tool does
Most "compressors" only turn the quality dial. Two things shrink a photo far more reliably: making it smaller in pixels, and choosing the right format. This page does all three and shows you the byte count each time, so you can stop when the picture still looks right.
How to use it
- 1 Drop in an image or pick one from your device.
- 2 Lower the quality, cap the width or height, or change the format.
- 3 Watch the byte count and download when it looks right.
Which format for which picture
The biggest saving usually comes from picking the right container, not from squeezing the wrong one harder.
| Format | Loses detail? | Use it for |
|---|---|---|
| JPEG | Yes | Photographs, anything with soft gradients |
| WebP | Yes | The same photos, usually 25-35% smaller |
| PNG | No | Logos, screenshots, anything needing transparency |
Why the file sometimes gets bigger
A JPEG that was already squeezed hard gains nothing from being decoded and re-encoded at high quality - it only picks up new artefacts and often more bytes. PNG ignores the quality slider entirely. When the result is larger, the tool says so instead of quietly handing you a worse file.
Transparency does not survive JPEG
JPEG has no transparent channel, so those areas have to become some colour. Left alone they turn black, which people usually discover after downloading. This page fills them with white instead - still a change, but the one you would have chosen.
Resizing beats squeezing
A 4000 pixel photo shown in a 800 pixel column is carrying five times more detail than anyone will see. Capping the width usually saves more bytes than any quality setting, and unlike quality it costs nothing visible at the size the picture is actually displayed.