Drag and drop or click to upload a JPG, PNG, or WEBP file. The photo is displayed at gamma 1.0 (no change) to start.
Gamma Correction
Lighten or darken your photo by adjusting the gamma curve. Values below 1.0 brighten, above 1.0 darken. Free, no signup.
How to Apply Gamma Correction to a Photo
Drag left (toward 0.5) to brighten the image or right (toward 2.5) to darken it. The label updates to show Brighten, Original, or Darken.
Click Download to save the gamma-corrected image as a PNG at the original pixel dimensions.
How gamma correction works
For every pixel channel value v (0–255), the corrected value is calculated as 255 × (v/255)^(1/γ). When γ is less than 1.0 the exponent 1/γ is greater than 1, which compresses the curve and brightens mid-tones. When γ is greater than 1.0 the exponent is less than 1, which expands the curve and darkens mid-tones. Because pure black (0) and pure white (255) are fixed points on the curve, gamma correction cannot clip highlights or crush shadows — making it gentler than a flat brightness slider.
When to use gamma correction
Underexposed photos — a gamma below 1.0 lifts shadows and mid-tones without blowing out bright areas. Overexposed photos — a gamma above 1.0 pulls back highlights while keeping shadows visible. Display calibration — monitors and cameras often encode images at a specific gamma; correcting for this restores accurate colour. Print preparation — images intended for print often need a gamma adjustment because printers and screens have different tonal response curves. Video frame editing — gamma correction is a standard step in colour grading workflows for adjusting exposure without full colour-correction software.