Adjust image contrast — add punch or soften a photo

How to use Image Contrast

1. Choose one or more photos.
2. Set Contrast from −100% to +100%. The default, +25%, gives a clear but gentle lift.
3. Pick Save as: the same format as the original, JPEG, PNG, WebP or AVIF, and a Quality for lossy formats.
4. Press Apply and compare the result with the original.

What it does and when to use it

A photo taken on a hazy day, through a window or of a faded print often looks grey and flat. Raising contrast restores depth. Lowering it does the reverse: it gives a soft, faded, matte look, or tames a harsh midday shot before you add text over it.

Small changes go a long way, and large values clip the brightest and darkest areas. Contrast works well combined with other tools. Fix overall lightness with Image Brightness, lift only the midtones with Image Gamma, or adjust colour strength with Image Saturation.

How it works

The tool builds a 256-entry table from the CSS contrast() formula and applies it to the red, green and blue values of every pixel. With c as the slider value:

output = (v − 127.5) × (1 + c ÷ 100) + 127.5, clipped to 0–255

At +100% the distance from middle grey doubles; at −100% every pixel becomes middle grey. Transparency is not changed. The photo is processed in a background worker in your browser; if you choose AVIF, the encoder downloads from this site the first time. Your photo is never uploaded.

Worked examples

These values come from the tool’s own formula.

• +25%, a warm pixel (200, 100, 50). Red: (200 − 127.5) × 1.25 + 127.5 = 218.1, so 218. Green becomes 93 and blue 31. The pixel is now (218, 93, 31): lighter lights, darker darks.
• −30%, the same pixel. It becomes (178, 108, 73), flatter and closer to grey. Pure white drops to 217, and pure black rises to 38, which gives the faded “matte” look.
• +100%, a light grey (220, 220, 220). It is pushed to 255, pure white. This is the clipping the FAQ warns about.

Limits and tips

• Middle grey (128) barely moves at any setting; contrast works around it.
• The change is global. To lift dark midtones while black and white stay fixed, use gamma instead.
• Saving as JPEG again adds a little compression each time, so edit once and save at a high quality.