Adjust Brightness & Contrast

Free Image Brightness and Contrast Adjustment Tool

Adjust brightness and contrast of your photos online for free with our easy-to-use image editor. Perfect for fixing underexposed or overexposed photos, enhancing image quality, improving visibility, correcting lighting issues, and creating dramatic effects. This tool features real-time preview so you can see changes instantly as you adjust sliders. Use auto-enhance for one-click optimization or manual controls for precise adjustments. All processing happens locally in your browser—no server upload required, ensuring complete privacy. Works with JPG, PNG, WebP and all common image formats. No watermark, no registration, unlimited use.

What is brightness and contrast adjustment?

Brightness adjusts the overall lightness or darkness of an image—making all pixels lighter or darker uniformly. Contrast adjusts the difference between light and dark areas—increasing contrast makes lights lighter and darks darker, while decreasing contrast makes the image appear flatter. Together, these adjustments are fundamental for correcting exposure issues and enhancing image quality.

When should I adjust brightness vs. contrast?

Adjust BRIGHTNESS when: your image is too dark (underexposed) or too bright (overexposed) overall, you need to shift the entire tonal range lighter or darker. Adjust CONTRAST when: your image looks washed out or flat, colors appear dull, you want to make details pop, you need more definition between highlights and shadows. Often you'll adjust both together for best results.

How does the auto adjust feature work?

The auto adjust feature analyzes your image's histogram to automatically calculate optimal brightness and contrast values. It identifies the darkest and lightest pixels, calculates the average brightness, and determines the tonal range. It then adjusts values to center the average near mid-tone (128 on 0-255 scale) and stretches the histogram for better contrast. This works well for most photos but manual fine-tuning may still be needed for specific artistic effects.

What do the brightness values mean?

Brightness ranges from -100 to +100. Negative values (-1 to -100) darken the image—useful for overexposed photos or creating dramatic effects. Zero (0) means no change—original brightness maintained. Positive values (+1 to +100) brighten the image—useful for underexposed photos or bringing out shadow details. Extreme values may cause loss of detail in highlights or shadows.

What do the contrast values mean?

Contrast ranges from -100 to +100. Negative values (-1 to -100) reduce contrast—creating a flatter, softer look with less difference between light and dark areas. Zero (0) means no change—original contrast maintained. Positive values (+1 to +100) increase contrast—making highlights brighter and shadows darker, creating a more dramatic, punchy look. High contrast can make images more vivid but may lose detail in extreme highlights or shadows.

Can I see changes in real-time?

Yes! This tool features live preview. As you move the brightness or contrast sliders, the preview updates instantly so you can see exactly how your adjustments affect the image before saving. This makes it easy to experiment and find the perfect settings. When you're happy with the preview, click 'Apply Changes' to finalize and download.

How do I fix an underexposed (too dark) photo?

For underexposed photos: 1) Start by increasing brightness (+30 to +70 typically works). 2) If the image looks flat, increase contrast slightly (+10 to +30) to restore depth. 3) Use the auto adjust feature for a quick starting point, then fine-tune manually. 4) Check the preview—if highlights blow out (turn pure white), reduce brightness slightly. The goal is to bring out shadow detail while preserving highlight information.

How do I fix an overexposed (too bright) photo?

For overexposed photos: 1) Start by decreasing brightness (-30 to -70 typically). 2) Increase contrast (+10 to +40) to recover detail and depth. 3) Check if highlights (bright areas) show detail—if they're pure white, they can't be recovered. 4) Focus on mid-tones and shadows. For severe overexposure, prevention is better than cure—the tool can help but can't create detail that wasn't captured.

Will adjusting brightness/contrast reduce image quality?

Moderate adjustments (-50 to +50) generally have minimal quality impact and are non-destructive to image data. Extreme adjustments (near -100 or +100) may cause posterization (banding in gradients) or clipping (loss of detail in highlights/shadows). Always work with high-quality originals. This tool preserves your original image format and doesn't compress more than necessary. For best quality, make adjustments once rather than repeatedly saving and reloading adjusted images.

Can I use this for professional photography?

Yes! This tool is suitable for professional use for quick adjustments, batch processing corrections, fixing client photos, preparing images for web, social media optimization, and real estate photography enhancement. However, for advanced professional work requiring more control (like RAW processing, curves adjustments, or selective adjustments), dedicated software like Lightroom or Photoshop provides more features. This tool excels at quick, high-quality brightness/contrast corrections without software installation.