Upload your photo
Click the drop zone or drag a JPG, PNG, or WebP file onto it. The image loads straight into a canvas on your device.
Image Brightness Contrast Adjuster
Upload a photo and dial in brightness and contrast independently with live sliders and an instant canvas preview.
Click to upload a photo
or drag and drop it here
JPG, PNG or WebP · processed entirely in your browser, never uploaded
How it works
Adjust brightness and contrast
Drag either slider from -100 to 100. Brightness adds or subtracts a flat offset per pixel; contrast applies the standard factor formula around mid-gray.
Download your edit
Both sliders always recompute from the original pixels, so you can nudge them freely, then export the result as a PNG.
FAQ
Is my photo uploaded anywhere?
No. All processing happens locally in your browser with the Canvas API, so your photo is never uploaded to a server.
What formula does the contrast slider use?
It uses the standard contrast-correction formula (factor = 259*(contrast+255) / (255*(259-contrast))) applied to each channel around the mid-gray point of 128.
Do brightness and contrast stack up if I move the sliders repeatedly?
No. Every slider move recalculates both effects from the original uploaded pixels, so the result always reflects the current slider values, never a compounded edit.