Adjust Photo Contrast

Add or reduce the separation between light and dark tones with one contrast slider, then save a JPEG.

How to adjust photo contrast

  1. Upload one image or PDF.
  2. Set Contrast (%) and check the preview. It starts at 125%; 100% leaves the photo unchanged, lower values soften it toward gray and higher values add punch.
  3. Download the JPEG.

What you can upload and what you get

  • One PNG, JPEG, WebP or GIF image, or a PDF, up to 100 MB. Only the first PDF page or GIF frame is used.
  • Transparent areas are filled with white before the change is applied.
  • Large images are resized automatically to fit 4 million processing pixels and 8,192 pixels per side, keeping their proportions. Smaller images are not enlarged. You get a high-quality JPEG; original file metadata is not kept.

Questions

What does the percentage mean?

Each color channel is pushed away from, or pulled toward, mid-gray by that percentage. 100% is unchanged, 200% doubles the difference from mid-gray and 0% turns everything mid-gray.

Can more contrast bring back detail in very dark or very bright areas?

No. Increasing contrast cannot restore detail in areas that are already pure black or white. Lower settings soften those tones, while high settings push more dark and bright tones to pure black or white.

Why can strong colors shift at high settings?

Red, green and blue are adjusted separately, so a channel that reaches its limit stops while the others keep changing. Saturated colors can look more intense or slightly different at high settings.