Adjust an image brightness and contrast locally - with sliders, format preserved. No upload.
Running locally on your device ...
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Your files never left your device
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
Brightness shifts every tone evenly lighter or darker; contrast widens or narrows the gap between light and dark areas around the midpoint. This tool applies both sliders in one step, so an image shot too flat or too dark can be brought to a balanced look quickly.
Set brightness and contrast each between -100 and +100 (0 leaves that value unchanged). Positive brightness lightens, negative darkens; positive contrast makes the image punchier, negative flatter. The output keeps your original format and dimensions - a PNG stays a PNG (with transparency), a JPEG stays a JPEG.
Everything runs entirely locally in your browser on a canvas (no upload, even offline) - your image never leaves your device. Very strong values can lose detail in the brightest and darkest areas (clipping); for a natural result, moderate adjustments usually suffice. Animated images are flattened to a single frame.
| Input formats | JPG, JPEG, PNG, WEBP |
|---|---|
| Output format | JPG |
| Batch processing | Yes |
| Processing | Locally in your browser (JavaScript) |
| File upload | None |
Limitations: Adjusts brightness (additive shift) and contrast (spread around the midpoint), each in the range -100 to +100; 0/0 leaves the image unchanged. The original format and dimensions are preserved (PNG keeps transparency; JPEG flattens onto white). Very strong values can clip highlights or shadows. Animated inputs are reduced to a single frame.
No. The adjustment runs entirely locally in the browser on a canvas - even offline. Your image never leaves your device.
With a slider at 0, that aspect is left unchanged. With brightness 0 and contrast 0 the result is identical to the input (apart from JPEG re-encoding).
Very high brightness or contrast can clip highlights to pure white and shadows to pure black, losing detail there. More moderate values avoid this.
Yes. A PNG stays a PNG (with transparency), a JPEG stays a JPEG, and the dimensions are unchanged.