What is image opacity?

Opacity is how solid an image looks. At 100% it hides whatever is behind it, at 50% half of the background shows through, and at 0% the image is invisible. PNG and WebP files store it for every pixel in the alpha channel, next to red, green and blue. A faded image is handy as a watermark, a soft background for slides and web pages, or an overlay in a design.

Tool description

Open an image and drag the Opacity slider. The preview shows the result over a checkerboard, so you see exactly how much shows through, and the before and after view compares it with the original. Download it as a PNG that keeps the transparency.

Parts that are already transparent stay that way: the tool multiplies each pixel's own opacity, so a pixel at 80% ends up at 40% when you pick 50%. The colors don't change.

Features

  • One slider, from invisible to unchanged
  • Keeps existing transparency and every pixel's color
  • Saves PNG or WebP with the transparency, or JPG over white
  • Runs in your browser, so the image stays on your device

Tips

  • Keep PNG or WebP as the format. JPG can't store transparency, so a faded image saved as JPG just looks pale on white.
  • For a watermark or a logo over a photo, 20% to 40% is usually visible without getting in the way.
  • Opening a JPG works too: the result is a PNG with the whole photo faded evenly.