Image Brightness Adjuster
Free online tool to easily adjust image brightness, contrast, exposure, and gamma. Quick correction with 6 presets, download as PNG/JPEG/WebP.
Image Brightness Adjuster
Upload an image to
adjust brightness
What is the Image Brightness Adjuster?
The Image Brightness Adjuster is a free online tool that lets you easily adjust the brightness, contrast, exposure, and gamma of photos and images. You can brighten dark photos, correct overexposed images, and transform images to your desired atmosphere.
Use it directly in your web browser without installing any software. All image processing happens in your browser, ensuring complete privacy protection. Adjust in real-time with sliders and download in various formats including PNG, JPEG, and WebP.
Use Cases
- Correcting dark indoor photos – When brightening photos taken in low-light environments to make them clearer
- Recovering backlit photos – When adjusting brightness and contrast of backlit portrait photos to make faces clearer
- E-commerce product image correction – When creating clean and professional product photos by increasing brightness
- Pre-SNS upload correction – When adjusting photo atmosphere before posting to Instagram or blogs
- Improving scanned document readability – When increasing contrast of scanned documents to make text clearer
- Recovering overexposed photos – When lowering exposure of overly bright photos to restore details
- Applying vintage effects – When creating a film camera feel by adjusting gamma and contrast
Key Features
- Brightness Adjustment – Freely adjust overall image brightness from -100 to +100. Make dark photos brighter or bright photos darker.
- Contrast Adjustment – Adjust the difference between light and dark areas to sharpen blurry photos or create a soft atmosphere.
- Exposure Adjustment – Adjust overall light intensity like camera exposure settings. Produces more natural results than brightness.
- Gamma Correction – Non-linearly adjust mid-tone brightness to enhance shadow details or emphasize highlights.
- 6 Presets – One-click correction with Bright, Dark, Natural, Vivid, Soft, and High Contrast presets.
- Multiple Download Formats – Download as PNG (lossless), JPEG (high compression), or WebP (next-gen).
- Complete Privacy Protection – All processing happens in your browser and images are never sent to a server.
How to Use
- Upload Image – Click the upload area or drag and drop a file to load an image. Supports PNG, JPG, WebP, and GIF formats.
- Set Adjustment Options – Move the brightness, contrast, exposure, and gamma sliders to apply desired effects. See results in real-time.
- Use Presets (Optional) – For quick correction, click preset buttons like ‘Bright’ or ‘Natural’.
- Download – Click the download button and select your desired format: PNG, JPEG, or WebP.
Adjustment Options Explained
Brightness
Adjusts overall brightness by adding or subtracting the same value from all pixels. Positive values brighten, negative values darken. The most intuitive adjustment method, but extreme values may cause detail loss.
Contrast
Adjusts the difference between bright and dark areas. Increasing contrast sharpens images, while decreasing creates a softer atmosphere. Useful for improving readability in scanned documents or text-heavy images.
Exposure
Adjusts overall light intensity like camera exposure settings. Works through multiplication rather than addition like brightness, producing more natural results. Effective for correcting backlit photos or dark indoor photos.
Gamma
Non-linearly adjusts mid-tone brightness. Gamma values greater than 1 brighten dark areas, while values less than 1 darken bright areas. Use for enhancing shadow details or fine-tuning overall atmosphere.
Preset Guide
- Bright – Suitable for dark photos. Makes overall brighter with brightness +30, contrast +10, exposure +15.
- Dark – Suitable for overexposed photos. Recovers details with brightness -30, exposure -15.
- Natural – Suitable for everyday photos. Natural enhancement with brightness +10, contrast +15, exposure +5, gamma 1.1.
- Vivid – Suitable for blurry photos. Increases sharpness with contrast +30, gamma 1.2.
- Soft – Suitable for portrait photos. Creates soft atmosphere with contrast -15, gamma 0.9.
- High Contrast – Suitable for artistic effects. Creates intense light-dark contrast with contrast +50.
Download Format Comparison
- PNG – Lossless compression maintains original quality. Supports transparent backgrounds. Large file size. Suitable for logos, icons, and screenshots.
- JPEG – Lossy compression with small file size. No transparent background support. Suitable for photos and SNS uploads. Saved at 92% quality.
- WebP – Next-generation format with smaller size than PNG/JPEG but high quality. Supported by most browsers. Suitable for web optimization.
Frequently Asked Questions
Are uploaded images stored on the server?
No, all image processing happens only in your web browser. Images are never transmitted to or stored on a server, and all data is completely deleted when you close the page. You can safely use it with images containing personal information or copyrighted content.
What’s the difference between brightness and exposure?
Brightness adds or subtracts the same value to all pixels (addition), while exposure multiplies pixel values by a ratio (multiplication). Exposure adjustment produces more natural results, but brightness adjustment is more intuitive. Using both together enables more precise correction.
When should I use gamma correction?
Gamma correction is mainly used for adjusting mid-tones. For example, increase gamma above 1 to enhance shadow detail, or decrease below 1 to emphasize highlights. It’s also useful for creating vintage effects or film-like atmosphere.
What’s the maximum uploadable file size?
You can upload files up to 10MB. Since browser memory is used, very large images may slow down processing. We recommend resizing large images before use.
Which download format should I choose?
Choose PNG to maintain original quality, JPEG to reduce file size, or WebP for optimal web performance. Images with transparent backgrounds must be saved as PNG or WebP to preserve transparency.
Can I revert to the original?
Yes, clicking the ‘Reset’ button returns all adjustment values to default (0) and restores the original image state. Original image data is preserved until you download or close the page.
Does it work on mobile?
Yes, it works perfectly on smartphones and tablets. The responsive design automatically adjusts to screen size, allowing you to operate sliders with touch and use comparison mode.