Brighten a dark photo or add punch with more contrast, watching the change live. Drop an image in, drag the two sliders, and download the adjusted copy. It all happens in your browser — nothing is uploaded — and you can reset to the original at any point by reloading the file.
How it works
Brightness shifts every pixel lighter or darker; contrast stretches or compresses the gap between light and dark tones. Both sliders run from −100 to +100, where 0 leaves the channel untouched. Positive brightness lifts shadows and highlights together, while positive contrast makes darks darker and lights lighter for a punchier image.
The two adjustments compound, so a small brightness lift plus a little extra contrast is often better than pushing either one hard. Extreme values clip detail — very high brightness blows out highlights to pure white, and very high contrast crushes shadows to solid black — so nudge gradually and stop when it looks right. The output keeps the source format, with transparency preserved for PNG and WebP.
Practical examples
Rescuing an underexposed photo
An indoor shot came out too dark. Raise brightness by about +25 and add roughly +10 contrast so it lifts without looking washed out.
Adding punch to a flat image
A foggy-looking landscape lacks depth. Leave brightness near 0 and push contrast to around +30 — the darks deepen and the scene gains dimension.
Softening a harsh scan
A document scan is high-contrast and harsh to read on screen. Lower contrast by about −15 and nudge brightness up slightly for a gentler, easier-to-read page.
Frequently asked questions
What is the difference between brightness and contrast?
Brightness moves all tones up or down together, making the whole image lighter or darker. Contrast changes the spread between light and dark — more contrast makes shadows deeper and highlights brighter, while less contrast flattens everything toward mid-gray.
What do the slider numbers mean?
Each slider is centred on 0, which means no change. Positive values increase brightness or contrast; negative values decrease them. The range runs from −100 to +100 so you can make both subtle and strong adjustments.
Why does the image look worse at extreme settings?
Pushing too far clips detail: maximum brightness turns highlights to pure white and maximum contrast crushes shadows to black, and those areas cannot be recovered. Small, combined adjustments almost always look better than one extreme setting.
Can I undo my changes?
Move the sliders back toward 0 to reduce the effect, or reload the file with “Choose another” to return to the untouched original. Your source file is never modified, so nothing is lost.
Does adjusting brightness lose quality?
The adjustment itself is a light-touch pixel operation, so quality holds up well within moderate ranges. Only extreme settings that clip highlights or shadows permanently discard detail in those areas.
Is transparency preserved?
Yes for PNG and WebP — transparent areas stay transparent and only the visible pixels are adjusted. JPGs have no transparency, so clear areas are filled with white.
Which formats are supported?
JPG, PNG and WebP. The download keeps the same format you started with.
Does it change colours or just lightness?
These controls affect lightness and tonal spread, not hue. Colours stay the same shade; they simply get lighter, darker or more separated. To remove colour entirely, use the grayscale tool.
Are my images uploaded to a server?
No. Every adjustment runs in your browser with the Canvas API. Nothing is uploaded, and it works offline once the page has loaded.
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