Brighten a dark picture, add some punch to a flat one, or turn it black and white. You see the change as you drag, and nothing is saved until you say so.
Drop it on the box above or pick it from your files.
Start with a preset if you like, then adjust. The picture updates as you go.
Press the button and you get a new file with the changes baked in.
If a picture looks flat or grey, contrast is usually the fix, not brightness. Brightness lifts everything equally, including the shadows that are meant to be dark, which is what makes an over-brightened photo look washed out.
If a photo was taken indoors under yellow light, pulling saturation down a little often looks better than trying to correct the colour directly.
For a photograph of a document, the clean scan preset is the useful one: high contrast and slightly reduced colour, which makes printed text read sharply and flattens out the shadow from your hand.
No. The work happens inside this tab, on your own machine. Open your browser's network tab while you use the tool, there is no request carrying your file.
Practical limits depend on the tool, browser and available device memory. Large files can fail even when no explicit limit is shown. Keep an original and use a smaller job if this device cannot finish it.
No, and there is no daily limit either. There is nothing to sign up for.
No. What you see is a preview on screen; the file on your device is only written when you press the button.
No. These are straightforward adjustments to brightness, contrast and colour, predictable, and the same every time.
Brightness runs from 40 to 180 percent, contrast from 40 to 200, saturation from 0 to 220, and there are separate amounts of black and white and of sepia from 0 to 100. Five presets give a starting point: Punchy, Soft, Black and white, Sepia and Clean scan. Moving any slider switches the preset back to None, so your own settings are never mixed with a preset by accident.
A live preview shows the result as you move the controls, and the saved file is made from the full size original, not from the preview.
Raise contrast a little before you raise brightness. Brightness alone makes a dark picture look washed out, while a touch of contrast gives it depth. Clean scan is a quick fix for a photographed document, because it lifts the paper towards white and darkens the text.
The filters change every pixel and the picture is saved again, so JPG and WebP lose a little each time. Make all your changes in one go and save once. Transparent areas turn white when you save as JPG. The tool does not crop and has no curves or per colour controls.