Brighten a dark photo

This image brightener lifts dark and backlit photos without the flat, gray look of a plain brightness slider. You pick one of three modes, set the strength, check the result with a before/after split, and download a brighter copy as JPG, PNG or WebP. Everything runs in your browser: the photo is processed on your device and is never uploaded.

What the tool does

Most "brightness" controls add the same amount to every pixel value. Blacks turn gray, colors lose saturation and the photo looks hazy. This tool works more like a camera's exposure:

• It converts the pixels to linear light, the actual amount of light the sensor recorded, and works there.
• It computes a new brightness for each pixel and scales red, green and blue by the same ratio, so hues stay true instead of washing out.
• Bright areas roll off softly toward white instead of clipping, and colors that would go out of range are pulled back gently rather than burning out one channel.

There are three modes:

Backlit is a local adjustment. The tool builds a soft, low-resolution map of how lit each part of the frame is, then raises the dark regions toward a mid level while leaving a bright sky or window as it was. It also blends in each pixel's own brightness, which keeps halos down along the edge between a dark subject and a bright background.

How to use it

1. Choose a photo with the picker above (or drag it in on a computer). JPEG, PNG and WebP work everywhere; HEIC works if your browser can decode it.
2. Pick a mode. Start with Natural; switch to Shadow lift or Backlit if the bright parts start to look too pale.
3. Set the strength from 0 to 100%. The default is 50%.
4. Drag the split across the preview to compare before and after on the same frame.
5. Choose the format (it defaults to the format of your original) and tap Download. The file is saved with -bright added to its name.

The preview is computed on a smaller copy so the slider stays responsive. When you download, the tool decodes the original again and brightens it at full size.

How to read the result

• Midtones look gray or flat? You are using too much Natural. Lower the strength, or switch to Shadow lift.
• Grain or color speckles in the shadows? That noise was already in the file; brightening reveals it. Use less strength, and start from the best copy you have: an original from the camera holds more shadow detail than a version recompressed by a chat app.
• Gray halo around a backlit subject? Lower the strength in Backlit mode until the edge looks natural.
• A notice about a large photo? Photos above about 16 megapixels are scaled down to stay within the browser's memory. The message shows the size that was saved.
• Smaller or larger file than the original? Normal: the image is re-encoded (JPEG and WebP at high quality). PNG files are lossless and can be much larger.

Doing it with the apps you already have

Every phone and computer has brightening tools built in. On iPhone, open the photo in Photos, tap Edit, then Adjust, and use Exposure, Shadows and Brilliance. Google Photos, the Windows Photos app and Photos on Mac have similar controls. Our guide on how to brighten a dark photo walks through each one and explains which slider to use when.

Use this tool instead when you want a quick result without installing anything, a side-by-side comparison, or a copy that leaves your library untouched.

Limits

• It cannot recover what was never recorded. Fully black shadows and blown-out highlights contain no detail to bring back.
• It is not a noise reducer or a sharpener. Heavy brightening of a very dark photo will show noise and banding.
• It works on the whole frame. There is no brush or selection. Backlit mode is local, but automatic.
• It does not create an HDR file. If you want highlights that glow on HDR screens, read what Ultra HDR is and use the Ultra HDR converter after brightening.

Keep the photos that matter in sigil.

A dark photo is often a document: a receipt shot in a dim room, an ID card, a medical letter. sigil. keeps photos like these in a vault encrypted on your phone with a 256-bit key that only the sign you draw on a 5×5 grid unlocks. It strips EXIF and location data on import and export, and its private camera keeps new shots out of your Camera Roll. See how it helps with ID documents.