Brightness Adjuster
Brighten or darken an image with a live preview slider. Runs entirely in your browser.
Adjust image brightness
Upload an image, then drag the slider to brighten or darken it. The preview updates instantly.
Drag & drop an image here, or click to browse
Supports JPG, PNG and WEBP.
Preview
Your image is processed locally in this browser tab using the Canvas API. It is never uploaded to Calcooo or any server.
How to use this tool
- Drag and drop an image into the box above, or click to browse and select one.
- Drag the Brightness slider left to darken, or right to brighten. The preview updates live.
- Use Reset to return to the original brightness at any time.
- Click Download image to save the result.
FAQ
Frequently asked questions
Is my image uploaded anywhere when I adjust brightness?
No. The image is processed locally in your browser using the Canvas API. It never leaves your device.
What does 100% brightness mean?
100% is the original, unchanged brightness of your image. Moving the slider below 100% darkens the image, and moving it above 100% brightens the image.
Does this change the file format?
No. The downloaded image is exported in the same format as the original file you uploaded.
Can I combine this with other adjustments?
This tool only adjusts brightness. If you also want to change contrast, saturation or convert to grayscale, see the other Image Editing tools, or use Image Filters to adjust all of them together on one page.