Image Brightness Adjuster
Rescue photos that came out too dark, or tone down ones that are too bright. Move a slider, or let the automatic exposure fix find a balanced setting for you, then download the corrected image.
- Files stay on your device
- No sign-up
- Free to use
Light
Brightness lifts or lowers everything. Midtones changes the middle greys while keeping pure black and white, which brightens dark photos without washing out highlights.
Output
How to use Image Brightness Adjuster
- Drop one or more photos onto the upload area.
- Select Auto fix exposure for a one-click correction, or drag the Brightness and Midtones sliders yourself.
- Hold the compare button to check the change against the original.
- Select Apply brightness and download the results.
Image Brightness Adjuster features
Brightness and midtones
Brightness shifts the whole image; Midtones lifts or lowers middle tones only, keeping blacks and whites intact.
Automatic exposure fix
Analyses the photo’s histogram and sets the midtone curve so the typical brightness lands in a natural middle range.
Highlight-friendly
Brightening through midtones avoids the washed-out, grey-black look of a simple brightness boost.
Live preview
Every change is shown immediately, and you can hold a button to see the original.
Batch processing
Apply the same correction to a whole set of photos from one shoot.
Private
Photos are corrected on your device, not on a server.
When to use Image Brightness Adjuster
- Brightening indoor or evening photos taken without a flash.
- Making backlit portraits, where the face is in shadow, easier to see.
- Darkening overexposed shots taken in strong sunlight.
- Making scanned documents and receipts more legible.
- Matching the brightness of several product photos before publishing.
Image Brightness Adjuster FAQ
What is the difference between Brightness and Midtones?
Brightness multiplies every pixel, so shadows, midtones and highlights all get lighter or darker. Midtones applies a curve that changes the middle tones most and leaves pure black and pure white where they are, which usually looks more natural.
Why do my bright areas turn white when I increase brightness?
Pixels can only get as bright as pure white. Pushing brightness too far makes light areas such as skies and skin reach that limit and lose detail, called clipping. Use Midtones instead for dark photos, as it lifts shadows without clipping highlights.
Can it fix a completely black photo?
Only partly. A very underexposed photo contains little information in its shadows, so brightening it reveals noise and colour blotches. The result can still be useful for seeing what is in the picture.
How does Auto fix exposure decide?
It measures the median brightness of the image, the level that half the pixels are darker than, and calculates the midtone curve that moves it close to the middle of the range. Very bright or very dark scenes, like snow or a night sky, may need manual adjustment afterwards.
Will this change the colours?
Brightening keeps colours’ proportions, so hues stay the same. Very strong changes can make colours look slightly less saturated; the Saturation Adjuster can compensate.
Brightness, exposure and the tone curve
Every pixel in a typical photo has three values from 0 to 255, for red, green and blue. Making an image brighter means raising those values, but there are many ways to do it. Adding the same amount to every pixel lifts blacks to grey and makes the image look flat. Multiplying by a factor keeps black at zero but quickly pushes light tones to the 255 limit. A curve that bends the middle of the range while pinning both ends, known as a gamma adjustment, avoids both problems, which is why the Midtones control is the better first choice for most dark photos.
Cameras make similar decisions when they choose an exposure. They measure the scene and aim for an average brightness, which is why snowy landscapes often come out grey and dark stages look bright: the camera assumed an average scene. Correcting afterwards works best when the original captured detail in the area you want to see. Shadows hold less information than highlights, so a dark photo brightened a lot will reveal grain.
The histogram, a chart of how many pixels sit at each brightness level, is the tool professionals use to judge exposure. A histogram bunched to the left indicates a dark image; one pressed against the right edge shows clipped highlights. The automatic fix here reads that distribution and targets its median, a simple and robust approach for everyday photos.
For the most natural results, adjust brightness first, then contrast and colour. Changing brightness alters how contrast and saturation are perceived, so working in that order avoids going back and forth between the tools.