Brightness & Contrast Adjustment
Fine-tune image brightness and contrast with precise controls.
Drop your image here
or click to browse · max 50 MB
Settings
wasm-vips (~5MB) will be downloaded on first use and cached by your browser.
Brightness & Contrast Adjustment
Adjusts image brightness and contrast levels. Brightness shifts all pixel values lighter or darker, while contrast adjusts the difference between light and dark areas. Both controls work together for precise exposure correction. Uses wasm-vips linear transformation for accurate results.
What is it used for?
- Correcting underexposed (too dark) or overexposed (too bright) photos
- Enhancing contrast in flat or hazy images
- Preparing images for printing (which often needs higher contrast)
- Matching brightness across multiple photos in a batch
- Creating high-contrast or low-contrast artistic effects
Step-by-Step Guide
- Click the upload area or drag and drop your image
- Adjust the Brightness slider (-100 to +100)
- Adjust the Contrast slider (0.2x to 3.0x)
- Choose your output format
- Click Convert to apply adjustments
- Preview and download the result
How it works
Upload an image and adjust the brightness and contrast sliders. Click Convert to apply the adjustments using wasm-vips linear transformation (pixel = pixel * contrast + brightness). Preview and download.
Tips & Best Practices
- Start with contrast adjustment, then fine-tune brightness
- Contrast 1.0x = no change; above 1.0 = more contrast; below 1.0 = less contrast
- For underexposed photos: increase brightness (+20 to +40) and slightly increase contrast (1.1-1.3x)
- For overexposed photos: decrease brightness (-20 to -40) and increase contrast (1.2-1.5x)
Frequently Asked Questions
What's the difference between brightness and contrast?
Brightness shifts all pixel values by a fixed amount (making everything lighter or darker). Contrast multiplies pixel values (increasing the difference between light and dark areas). They work together for proper exposure correction.
Can I reset to the original values?
Yes, click the 'Reset to defaults' link to restore brightness to 0 and contrast to 1.0x.
Why does increasing contrast also appear to change brightness?
Contrast multiplies pixel values around their midpoint. High contrast makes darks darker and lights lighter, which can shift the perceived overall brightness.
Privacy & Security
This tool uses wasm-vips (libvips compiled to WebAssembly). The WASM binary (~5MB) is downloaded on first use and cached by your browser. All image processing happens locally on your device - your images are never uploaded to any server. This makes it safe for sensitive, private, or confidential images.