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How to Compress JPG Images Without Losing Visible Quality

Last updated: 2026-10-30

Make JPG files several times smaller while keeping them looking the same, and know when to change format instead.

Open the Image Size Compressor →

The two levers: dimensions and quality

File size depends mainly on how many pixels an image has and how much detail the JPG encoder keeps. A 4000 × 3000 phone photo has 12 million pixels; a website rarely needs more than 1600 pixels across. Reducing dimensions first often gives the biggest saving with no visible loss on screen.

JPG quality controls how much fine detail is discarded. Between 70% and 85% most photos look virtually identical to the original, while being a fraction of the size. Below about 50%, blocky artefacts start to appear around edges and in skies.

Step by step

  1. Open the Image Compressor and choose your image.
  2. If the image is very large, tick "Also change dimensions" and set a sensible width (for example 1600 px for the web, 1200 px for email).
  3. Choose "Quality" and start at 80%, or choose "Maximum KB" if you have a specific limit.
  4. Compress, compare the size shown with the original, and zoom into the preview to check details.
  5. Download when you are happy.

When to switch format

  • Screenshots, logos and diagrams with sharp text: PNG keeps edges crisp; JPG may blur them slightly.
  • Photos for websites: WebP is usually noticeably smaller than JPG at similar quality. Use the WebP Converter.
  • PNG photos: converting to JPG usually reduces size dramatically. Use PNG to JPG.

Good habits

  • Keep your original. Compression permanently discards detail.
  • Don't compress the same JPG repeatedly — each round loses a little more quality. Start from the original each time.
  • Compressed copies made with CentralMirror do not include camera metadata such as GPS location, which is a privacy bonus when sharing.

Tools mentioned in this guide