How to compress and convert images
- Drag images onto the drop area or press Choose images. You can add several at once.
- Pick an output format: JPEG, WebP or PNG.
- Set the quality. Values around 70 to 85 are a common starting point for photos.
- Optionally enter a maximum width to scale large images down. The aspect ratio is preserved.
- Compare the original and new sizes, then press Download for each image you want.
How browser-based compression works
Each image is decoded by your browser, drawn onto an HTML canvas at the target dimensions, and then re-encoded with the canvas toBlob method in the format you choose. For JPEG and WebP, the quality value tells the encoder how much detail it may discard: lower values produce smaller files with more visible artefacts. PNG is lossless, so the only ways to shrink it here are smaller dimensions or a different format. Because JPEG does not support transparency, transparent areas are filled with white when converting to JPEG.
Resizing usually saves the most. A photo straight from a phone camera is often several thousand pixels wide, while a blog layout may display it at well under 2,000 pixels.
Which format should you use?
| Format | Best for | Transparency |
|---|---|---|
| JPEG | Photos where maximum compatibility matters, including email and older software | No |
| WebP | Photos and graphics on websites; supported by all current major browsers | Yes |
| PNG | Screenshots, logos, diagrams and images with sharp edges or text | Yes |
Always check the result at full size before replacing an original, especially for images with fine text or gradients, and keep a copy of the untouched file.