How to compress an image
- Add your images. Choose them, drag them onto the box, or paste a screenshot with Ctrl+V / ⌘V. Batches work.
- Pick how small. Keep the quality slider around 75 for photos, or switch to Target size and type the limit in KB if a website asks for one.
- Check the result. Each image shows the old and new size. Compare opens a before/after slider so you can zoom in on faces and text.
- Download. One file at a time, or all of them as a ZIP. Change a setting and every image is redone automatically.
Which settings to use
| You have… | Format | Setting | Why |
|---|---|---|---|
| Photos for email, chat or a website | Same as original (JPG) | Quality 70–80 | Most people cannot see a difference from the original at this level; the file is usually several times smaller. |
| A form that says “max 100 KB” | JPG | Target size: 100 KB | The tool searches for the highest quality that fits, and only shrinks the dimensions if quality alone is not enough. |
| Screenshots, logos, diagrams | PNG | Smart PNG (default) | Reducing to 256 colours keeps text sharp and often removes more than half of the bytes. |
| Images for your own website | WebP or AVIF | Quality 70–80 | Both are supported by current browsers and are smaller than JPG at the same visual quality. |
| iPhone photos (HEIC) | JPG | Quality 80 | JPG opens everywhere; HEIC does not. |
What makes this compressor different
- Real encoders, not the browser’s quick one. JPG files are made with MozJPEG (trellis quantisation, optimised Huffman tables, progressive scans). PNGs go through colour quantisation and OxiPNG. Many online tools use the browser’s built-in
canvas.toBlobencoder, which produces larger files at the same quality. - Exact sizes in KB. Type a maximum (and a minimum, if the form has one) and get a file that is guaranteed to be under it. See compress to a size in KB.
- Nothing leaves your device. Images are processed in a Web Worker in this tab. There is no server that could keep, scan or leak them.
- Honest results. If re-encoding would make a file bigger (it happens with images that are already well compressed), the original is kept and you are told so.
How much smaller will my images get?
It depends on what the image is and how it was saved. A photo straight from a phone camera is saved at very high quality, so it typically shrinks the most. An image that was already compressed for the web may barely change, and a JPG that is saved again and again slowly loses detail without getting much smaller. Each result shows the exact bytes before and after, so you never have to guess.
Tip: if a file must be under a fixed size, resizing usually helps more than lowering the quality. A 4000-pixel-wide photo has four times as many pixels as a 2000-pixel one. Use Dimensions → Longest side.