Compress JPG

Shrink JPG photos with MozJPEG for smaller files at the same visual quality. Set a quality or a maximum size, compare before and after, and batch download. No upload.

Reviewed by Dany, RightSums team · Updated

Runs in your browser. Your files are not uploaded.

pdf-images · PDF tool · UK & US

Compress JPG re-encodes your photos with MozJPEG, an encoder built by Mozilla to squeeze more out of the JPG format than the standard encoders in cameras, phones and browsers. It uses progressive encoding and trellis quantisation, so at the same quality setting the file is usually noticeably smaller. Set a quality from 10 to 95, where 75 is a good default for photos you share, or give a maximum size such as 500 KB and let the tool find the highest quality that fits. Capping the longest side at 1920 or 2560 pixels shrinks phone photos further. HEIC, PNG and WebP files added here are saved as JPG, with any transparent areas filled with white. Location, camera and date details are removed. A before and after slider lets you check detail at full size. Nothing is uploaded.

Accepted inputs

  • JPG
  • HEIC
  • PNG
  • WebP
  • GIF
  • BMP
  • TIFF
  • AVIF

Outputs

  • JPG
  • ZIP archive

How to use the Compress JPG

  1. Add one or more JPG photos.
  2. Set the quality, or switch to Target file size and enter a limit.
  3. Optionally cap the longest side.
  4. Click Compress and download each JPG or a ZIP of all of them.

Frequently asked questions

What JPG quality should I use?

75 suits most photos for email, messaging and websites: the file is far smaller and the difference is hard to see. Use 85 to 90 for prints or photos you may edit again. Below 60, skies and skin tones start to show blocks and banding, so check the preview.

Why is MozJPEG better than a normal JPG save?

MozJPEG spends more computing time choosing how to store each block of the image. Progressive encoding and trellis quantisation produce files that are often 10% or more smaller than a standard encoder at the same visual quality, and the files open in every app that reads JPG.

Can I compress a JPG to a set size?

Yes. Choose Target file size and enter the limit in KB or MB. The tool searches quality levels to find the highest one under the limit and, if allowed, reduces the dimensions when quality alone is not enough. Each file shows whether it met the target.

Does compressing a JPG again lose more quality?

Yes, a little each time, because JPG is a lossy format. Compress from the best original you have rather than from a copy that has already been compressed, and keep the original if you might need it later.

Are my images uploaded?

No. Every image is decoded, processed and saved inside your browser using WebAssembly encoders, so the files never leave your phone or computer. You can switch off your internet connection after the page loads and the tool still works.

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