Adjust Image Brightness – Free Online Tool
Adjust brightness and contrast of images. Make your photos lighter or darker.
Example Output
Pixel-by-pixel brightness adjustment via CSS filter.
Visibly lighter photo with restored midtones
What is Adjust Image Brightness?
Adjust Image Brightness lifts shadows or pulls down highlights with a simple slider. Combined with contrast for two-axis tonal control. Useful for rescuing underexposed photos, prepping screenshots for print, and normalising image batches that vary in lighting.
Why use this tool?
- No API keys to manage and no rate limits to monitor
- 100% free with no hidden costs or daily limits
- Works offline after the first page load
- Supports PNG, JPG, WebP, GIF, and SVG with consistent quality across formats
- Your original file is never uploaded — sensitive screenshots stay on your device
How to use
- Drop an image
- Drag brightness slider (-100% to +100%)
- Preview updates live
- Combine with contrast/saturation sliders for full tone control
Examples
Rescue an underexposed photo
Indoor photo too dark — brightness +25% restores the subject without specialised software.
Print prep
Print output is often darker than screen. Boost brightness +10-15% before printing.
Common use cases
- Fixing underexposed or overexposed photos
- Preparing screenshots for print (which renders darker)
- Normalising batch images for a uniform look
- Subtle mood/tone adjustments
Troubleshooting
- Image looks washed out after boosting brightness.
- Lower contrast or saturation got skewed. Pair brightness with contrast adjustment for natural results.
Frequently Asked Questions
Upload your image and use the brightness slider. Values below 100% darken the image, 100% keeps the original, and values above 100% brighten it. The preview updates in real-time.
Try these related tools
Explore more Image Tools
Discover other free, privacy-first tools in Image Tools.