Brightness & Contrast
Adjust an image's brightness and contrast. Runs entirely in your browser.
Click to upload or drag and drop
Select an image file
How the adjustment works
Both sliders run from 0% to 200%, and 100% leaves the image unchanged. The preview updates instantly with a CSS filter; the file you download is re-rendered at the image's full original resolution about 0.3 seconds after you stop moving a slider, so there is no separate Apply step.
A practical example
An underexposed indoor photo often improves at around 120% brightness and 110% contrast. Values near either end clip: pixels pushed to pure white or black lose detail that can't be recovered in a file you've already saved, so keep the original.
Output and limits
PNG images stay PNG and keep their transparency; every other image type your browser can open is saved as a JPEG at 92% quality, named like photo-adjusted.jpg. Files over 50 MB are rejected. The saved file is rendered with your browser's canvas filter support, so if a download ever looks different from the preview, try a current version of Chrome, Edge or Firefox.
What the numbers do
- Both sliders start at 100% every time you load an image, and moving one back to 100% undoes its effect.
- Brightness scales how light the picture is: 80% is a fifth darker, 150% is half again as bright, and 0% gives a solid black image.
- Contrast above 100% pushes light and dark tones further apart, and below 100% squeezes them toward mid-gray.
- The two settings are applied together, brightness first and then contrast.
File names and when the download is ready
A file called holiday.jpg is saved as holiday-adjusted.jpg, and logo.png as logo-adjusted.png. A Continue to download button appears about 0.3 seconds after you stop moving a slider, once the file has been rendered, and each pause replaces that render with a fresh one. The button opens a download page with the file, and its Adjust the settings button brings you back to the sliders. The JPEG is written at 92% quality, so it is re-encoded even if you leave both sliders at 100%.
What it does not do
There are no separate controls for highlights, shadows or color, and no history beyond putting the sliders back to 100%. Only one image is processed at a time.
Frequently asked questions
What do the percentages mean?
100% is the original, unchanged image for both sliders. Below 100% reduces brightness/contrast; above 100% increases it.
Does moving the sliders change my original file?
No. Your original is never modified. Each time the sliders settle, a new adjusted copy is created in the browser, and that copy is what you download.
Why is there a short delay before the download button appears?
The preview changes instantly, but the full-resolution file is rendered about 0.3 seconds after the last slider movement, so the browser does not re-encode the image on every step of a drag.
Can I adjust several photos at once?
No. Load one image, set the sliders, download, then repeat for the next file.