Image Brightness
Adjust image brightness online by setting a custom factor between 0.0 and 3.0 to brighten or darken your pictures.
Run tool
Adjust the lighting of photos and graphics directly with this online brightness tool. The utility accepts base64-encoded image data and applies a numeric brightness multiplier ranging from 0.0 to 3.0. A multiplier of 1.0 preserves the original exposure levels of the photo. Values between 0.0 and 0.9 reduce illumination to create darker tones, where 0.0 completely darkens the visual content to black. Values between 1.1 and 3.0 brighten dark captures, highlight shadow details, and correct underexposed pictures. If no custom factor is entered, the tool automatically applies a default multiplier of 1.5 for a moderate brightening effect. During processing, original pixel dimensions remain unchanged. The result retains the initial image format when possible, or exports as a standard PNG graphic. You can copy or download the modified base64 output immediately for web development, design mockups, or quick photo corrections.
Instructions
- Provide your base64-encoded image string or upload an image file into the image input area.
- Enter a brightness factor between 0.0 and 3.0, or leave the field blank to use the default value of 1.5.
- Run the adjustment to process the image data.
- Review the preview and copy or download the adjusted base64 image data from the output area.
Examples
- Brighten a dim photo by uploading the base64 image string and applying a factor of 1.8 to reveal shadow details.
- Darken an overexposed graphic by entering the base64 image data and setting the factor to 0.7 for deeper contrast.
FAQ
What brightness factor value keeps the image unchanged?
Setting the factor to 1.0 maintains the original exposure level of your image without altering its pixel brightness.
What happens if I do not specify a brightness factor?
The tool uses a standard default factor of 1.5, which moderately brightens the input image.
What are the allowed minimum and maximum values for the factor?
The brightness multiplier is bounded between 0.0 and 3.0, where 0.0 produces a completely black image and 3.0 applies maximum brightening.
Does adjusting image brightness change the dimensions or file format?
The image dimensions remain unchanged. The tool preserves the original format when available, or outputs a PNG graphic otherwise.