Transparency Checker
See if a PNG has an alpha channel
Runs in your browser. Files never leave your device.
How to use Transparency Checker
- Choose or drop your images. You can add several at once.
- Adjust the settings and check the preview.
- Download the result, or every file at once as a ZIP.
About this tool
Check whether a PNG, WebP, GIF or other image really has transparency. See whether the file has an alpha channel, what share of the pixels are fully or partly transparent, and where they are, highlighted in a color of your choice.
The alpha mask view shows transparency as black and white, and the tool also reports the area that holds visible content, handy before trimming empty borders.
- Works on your device. Nothing is uploaded.
- Free, with no sign-up and no watermark.
- No limits on file count or size beyond what your device can handle.
Questions and answers
Why does my PNG have a white background instead of transparency?
Some PNGs have an alpha channel but every pixel is opaque, or the background was saved as white. The checker tells you which is the case.
Can JPG files be transparent?
No. JPG has no alpha channel. Use PNG, WebP or AVIF for images with transparency.
Is Transparency Checker free?
Yes. Every tool on ImgImage is free to use, with no sign-up, no watermark and no limit on how many files you process.
Are my files uploaded anywhere?
No. Your files are processed by your own browser and never leave your device. Nothing you open here is sent to a server.
Does it work on my phone?
Yes. It works in any modern browser on phones, tablets and computers. Large files are processed faster on a computer.