Add Alpha Channel to PNG
Give a flat PNG a transparency channel and set its opacity. Runs entirely in your browser, so your data never leaves your device.
Drop a file here, or click to browse
Files never leave your device
Output
The result appears here as you type.
How to use Add Alpha Channel to PNG
- 1. Upload the PNG to modify. Add a PNG that currently has no transparency information, such as a flattened export from a photo editor or a screenshot saved without an alpha channel.
- 2. Set the alpha value. Move the Alpha value slider between 0, fully clear, and 255, fully opaque. Every pixel in the image receives this same uniform transparency value.
- 3. Download the PNG with transparency. Download the result once the preview confirms the new opacity level. The file now carries a real alpha channel that other tools and layouts will respect.
When to use Add Alpha Channel to PNG
Add Alpha Channel to PNG gives a flat, fully opaque PNG a uniform transparency channel set to whatever level you choose. It is for images that were exported without alpha support but now need to blend or fade against something else.
- Fading a background image behind text. A hero background photo needs to sit at partial opacity so overlaid headline text stays readable. Setting a mid-range alpha value gives the whole image a consistent fade.
- Preparing a watermark base image. A logo exported as a solid PNG needs to become semi-transparent before it is layered as a watermark. A uniform alpha value turns the flat file into a translucent overlay ready for compositing.
- Fixing a PNG that lost its transparency. Some export pipelines flatten transparency to a solid white or black background. Adding an alpha channel restores a usable transparency layer, even if it is uniform rather than per-shape.
Examples
Half-transparent
Input
photo.png + alpha 128
Output
photo.png with a uniform 50% alpha channel
About the Add Alpha Channel to PNG tool
Add Alpha Channel to PNG runs as plain JavaScript in your browser tab, with no server behind it. Give a flat PNG a transparency channel and set its opacity. Whatever you put in stays on your device from start to finish.
The tool is part of EditSafely's PNG Tools section, 108 single-purpose utilities built around the same idea: open the page, get the result, keep your data to yourself.
You can shape the output with the Alpha value (0 = clear, 255 = opaque) setting, and the result refreshes the moment you change it. The finished file is put together in browser memory and saved with the Download button, so it never touches a server on the way to your disk. A worked example further down the page shows exactly what the tool produces for a real input.
That local-first design has practical benefits beyond privacy. The tool keeps working on a flaky connection once the page has loaded, results are instant because nothing round-trips to a server, and it is safe to use with confidential material.
Frequently asked questions
Is Add Alpha Channel to PNG free to use?
Yes, it is completely free. All 2,658 tools on EditSafely work without an account, a subscription or usage limits.
Are my files uploaded to a server?
Everything happens locally. Your browser downloads the tool's code once, then does all the processing itself; nothing you enter is transmitted, stored or logged. You can even go offline after the page loads and it will still work.
Which files does Add Alpha Channel to PNG accept?
It accepts PNG images. There is no file size cap imposed by a server; very large files are limited only by your device's memory.
Do I need to sign up or install anything?
No. The tool works in any modern browser on desktop, tablet or phone. There is no account to create, no extension to add and no software to install.
How do I save the output?
Click the Download button once the result is ready. The file is built in your browser's memory and handed straight to your downloads folder, without passing through a server.