Darken a photo by a chosen percentage while keeping its colours true, or fade it evenly to make a background for text. Live preview, batch, no upload.
Moves every pixel towards black by the percentage you choose. With Keep colours on, the tool converts each pixel to hue, saturation and lightness, lowers only the lightness, and converts back, so a red car stays the same red, only deeper. With it off, the same amount is subtracted from red, green and blue directly, which darkens faster and lets colours slide towards grey and then black, the look you want for a dimmed backdrop behind a headline.
You need a hero image for a landing page with white text over it. The original 1920 × 1080 photo has a bright sky at 230 that would make the text unreadable. Darkening by 45% with Keep colours off drops that sky to about 115 and the mid-tones to 60; white text at 255 now has more than the 4.5 to 1 contrast ratio accessibility guidelines ask for. For a product photo that just came out a little too bright, 15% with Keep colours on is enough, and the product’s colour stays accurate for the listing.
Use it for backgrounds behind text, for toning down an over-bright photo without touching its colour, for making a series of images match a darker one, and for quick mood changes. Because it moves everything, it is not the right tool when only the highlights are too bright; there, Change Exposure at a small negative value is more natural. If you want the edges dark and the centre untouched, that is Vignette Effect. For the opposite direction, Lighten Image is the same tool in reverse.
Darkness runs from 0 to 100 percent; the chips cover the usual stops and 100 is solid black. Keep colours chooses between the HSL lightness shift, which preserves hue and saturation, and a plain RGB subtraction, which is stronger and desaturates. Try both on the preview; the difference is obvious on saturated subjects and subtle on neutral ones. The Output section sets the file type and quality; Same keeps what you dropped. Batch mode applies one darkness to every file.
What does Keep colours actually change? With it on, the tool lowers only lightness in HSL space so hue and saturation are untouched. With it off it subtracts the same number from every channel, so saturated colours lose intensity as they darken.
Can I darken just one area? No. This tool darkens the whole image evenly. For a soft dark edge use Vignette Effect; for a chosen region, crop, darken and merge it back with Overlay Image.
Why is 50% not half as dark as it looks? Perception is not linear. A 50 percent lightness drop looks like a strong but not extreme change. For a text background people usually land between 40 and 60.
Is anything uploaded? No. The adjustment runs in the browser and nothing is sent to a server.