Brighten or darken a photo in camera stops, from −1 EV to +1 EV. The same maths as the exposure slider in a raw editor, running in your browser.
Scales every pixel by a power of two, the way real exposure works: +1 EV doubles the light, −1 EV halves it, and +0.5 EV is about 1.4 times. The slider is marked in hundredths, so 50 means +0.5 EV. Compared with the plain percentage in Change Brightness, exposure values are easier to reason about if you know cameras, and the steps feel evenly spaced to the eye: each equal move on the slider looks like an equal change in brightness.
A concert photo shot at ISO 3200 comes out one stop under; the singer’s face averages pixel value 55. Setting exposure to +1 EV (100 on the slider) doubles that to 110, which is a normal skin value, and the black stage background stays black because 5 doubled is still only 10. Going the other way, a snowy scene where the snow sits at 235 and looks grey-white does not want a negative value, which only makes it greyer; it needs +0.3 EV, which pushes the snow to 255 while the shadows in the footprints move from 90 to 111 and keep their shape.
Use it for photos that are simply under- or over-exposed by a known amount, and for matching two photos taken at different settings so they sit together in a collage or a slideshow. Because it multiplies, it cannot bring back highlights that are already at 255; a blown-out sky stays blown out at −1 EV. For a picture where the shadows are dark but the highlights are fine, Adjust Gamma is the better curve. For scans and screenshots that need tone separation rather than more light, use Brightness & Contrast.
Exposure runs from −1 EV to +1 EV; the display shows the value in stops. The chips jump by common increments of a quarter, a half and a full stop. The tool warns near +0.7 EV because that is typically where bright areas start to clip. In the Output section, Same keeps the original file type; pick WebP for a smaller file. Batch mode applies one exposure change to every photo in a folder, handy for a whole set shot with the wrong ISO.
What does EV mean? Exposure value. One EV is one stop, a doubling or halving of light, the same unit as the exposure compensation dial on a camera.
Why does +1 EV look like less than double? Screens and eyes respond roughly logarithmically, so a doubling of pixel values reads as one noticeably brighter step rather than twice as bright. That is exactly why photographers use stops.
Can it recover an overexposed photo? Only partly. If a region is already at 255 in the file, no information is left to recover; darkening turns it grey, not detailed. Anything below 255 is preserved and scales correctly.
Is anything uploaded? No. Processing happens in the browser on your own device and the page works offline once loaded.