Show GIF Alpha Mask
Render each frame's transparency as a black-and-white alpha mask. 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 Show GIF Alpha Mask
- 1. Upload the GIF. Drop in or browse for the animated GIF whose transparency you want to inspect. Every frame is decoded so its alpha channel can be converted into a visible mask.
- 2. Read how the mask is built. Each pixel's opacity is mapped straight to a shade of gray: fully opaque pixels turn white, fully transparent pixels turn black, with no options to adjust for this tool.
- 3. Download the mask GIF. Download the resulting grayscale GIF. It plays back with the exact same timing as the original but shows only where transparency lives across the animation.
When to use Show GIF Alpha Mask
Show GIF Alpha Mask converts an animated GIF's transparency into a black-and-white matte, frame by frame, so you can see exactly where the see-through areas are. It solves the problem of transparency being hard to judge just by eye. Everything runs locally in your browser.
- Debugging an export that lost transparency. A GIF that should have a transparent background looks fully opaque when played. Viewing its alpha mask instantly shows whether any transparency survived the export at all.
- Checking a matte for compositing work. Before compositing an animated GIF over different backgrounds, viewing its alpha mask confirms the transparent region has clean edges rather than stray semi-transparent pixels.
- Comparing transparency across frames. An animation where the transparent area should stay constant sometimes flickers frame to frame. Viewing the alpha mask across the whole GIF reveals which frames are inconsistent.
Examples
Inspect transparency
Input
animation.gif
Output
A grayscale GIF where white is opaque and black is transparent.
About the Show GIF Alpha Mask tool
Show GIF Alpha Mask is a free online tool that works entirely inside your web browser. Render each frame's transparency as a black-and-white alpha mask. Because the processing happens on your own device, nothing you enter is uploaded, logged or stored anywhere.
This page is one of 110 GIF utilities on EditSafely. Each one does a single job well, and all of them follow the same rule: your input stays on your machine.
There is nothing to configure. Provide the input and the result appears on its own. 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.
Because nothing leaves your device, the tool is suitable for sensitive content such as internal documents, credentials or customer data. It also responds instantly, since every keystroke is handled on your own machine rather than by a remote API.
Frequently asked questions
Is Show GIF Alpha Mask 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 Show GIF Alpha Mask accept?
It accepts GIF animations. 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.