Online Tool Store
Change PNG Brightness
Upload a PNG, drag the slider to brighten or darken it, then reset or download instantly. Transparency preserved, runs entirely in your browser.
This works right here on your device — nothing gets sent out.
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Result
Example shown — upload your own PNG to adjust its brightness.
How it works
- Upload a PNG by dragging it into the drop zone or clicking to browse.
- Drag the brightness slider left to darken or right to brighten — the preview updates live.
- Click Reset at any time to instantly revert to the original, unedited image.
- Download the brightness-adjusted result as a PNG.
Adjustment reads the image's pixel data via the canvas API and adds the chosen offset to each pixel's red, green, and blue values (clamped to 0-255), leaving alpha untouched — the same math behind a brightness slider in any photo editor.
FAQ
Is my image uploaded anywhere?
No. Brightness is adjusted entirely in your browser using the canvas API — your PNG is never sent to a server.
Does it preserve transparency?
Yes — only the RGB channels are adjusted. The alpha channel is left untouched.
What range can I adjust brightness by?
From -100 (much darker) to +100 (much brighter), with a live preview as you drag the slider.
Does this reduce image quality?
No — pixel values are adjusted directly; resolution and compression stay the same.
Can I undo a brightness change?
Yes — a Reset button appears as soon as you move the slider, and it instantly restores the original, unedited image.
Can I darken a PNG as well as brighten it?
Yes — drag the slider left of center to darken the image, or right of center to brighten it.
What file size or dimensions does it support?
Any PNG works. Very large images (over 2000px on a side) are automatically downscaled for a responsive preview before adjustment.
How we compare
| Feature | Online Tool Store | OnlinePNGTools | SmallPNGTools | Zight |
|---|---|---|---|---|
| Free forever — no premium paywall or download delay | ✓ | Premium plan removes download delays | ✓ | ✓ |
| One-click reset to the original image | ✓ | Before/after preview only, no reset button | ✓ | No reset or comparison feature |
| Transparency (alpha channel) preserved | ✓ | Not stated | ✓ | Not stated |
Full image editors are the right call for complex edits. PNG Brightness Changer is for the one-off case — a quick brightness fix — done in one upload with no install.