How to use the image compressor
- Select image files. You can choose several at once.
- Set the quality, maximum width and output format.
- Press Compress to see the reduced file sizes and save each file.
How the image compressor works
JPEG and WebP use lossy compression that removes information that is hard to notice, so lowering the quality value shrinks the file a lot but also lowers image quality. This tool redraws the image on your browser's canvas and saves it at the chosen quality. Setting a maximum width scales the image down while keeping its proportions, which reduces the file size a lot. In general, a quality of 70 to 85 cuts the file to under half with little visible difference. PNG is lossless, so the quality value does not apply and the size shrinks only when you reduce the dimensions. Images are never uploaded and are processed only on your device.
Differences between formats
JPEG suits photos and opens almost anywhere. WebP gives smaller files at the same quality but may not open in very old programs. PNG is good for transparency and sharp graphics, but photos are large. When you save as JPEG, transparent areas are filled with white.
Tips
- For photos on a blog or website, a width of 1,600 px or less and a quality of about 75 is a solid choice.
- When an email attachment or upload has a size limit, try reducing the dimensions first.
- Photos suit JPEG or WebP; logos and transparent backgrounds suit PNG.
- Keep the original separately and save the compressed copy as a different file.
Notes & limitations
Compression costs image quality, so do not delete your originals. Processing very large images or many files at once can slow your device. Metadata such as location information in photos is removed during compression.
FAQ
Are my images uploaded to a server?
No. All processing happens inside your browser.
The file got bigger after compressing.
An image that is already well compressed, or a PNG, can grow when saved again. Lower the quality or reduce the size.
Is a transparent background kept?
It is kept for PNG and WebP, and becomes a white background when saved as JPEG.