What quality should I choose?
| Quality | Use it for |
|---|---|
| 85-92 | Printing, archiving, and photos you will edit again. |
| 70-80 | Websites, email and social media. The best balance - the default is 75. |
| 50-65 | Thumbnails, previews and attachments where size matters more than detail. |
Combining a lower quality with a smaller pixel size saves the most. A 4000 px phone photo resized to 1920 px and saved at 75 is typically under 400 KB.
Why MozJPEG makes smaller files
MozJPEG is a JPEG encoder developed by Mozilla. It produces standard JPG files that open everywhere, but encodes them more cleverly: progressive scans, optimised Huffman tables and trellis quantisation. The result is noticeably smaller than what a camera, phone or image editor writes at the same quality setting.
How to compress a JPEG
- Drop your images onto the box above, click it to choose them, or paste a screenshot.
- Check the settings. They are already set for this task, and you can change any of them.
- Download each image, or all of them at once as a ZIP. Click a thumbnail to compare before and after.
Images are processed as soon as you add them. Change a setting and press Apply to all again to redo the batch.
How your files stay private
Most free converters upload your file, process it on their server and send the result back - so a copy of it passes through somebody else's machine. This page does all of the work in your browser instead. The files you choose are read into memory on your own device, processed there and handed back as a download; none of their contents is transmitted. You can switch off Wi-Fi after the page has loaded and it keeps working.