Just drag & drop a file if it is just one file like an animated GIF, APNG, or WebP.
2. If you have no images or videos with transparent backgrounds but just with green or blue backgrounds, you can use the Chromakeying filter in Honeycam to make green or blue backgrounds transparent.
3. Now just click the Save button and you will have the video with transparent backgrounds!
Click the Save button and select the format as WebM.
You can check how it looks on the browser by clicking the [Show on browser] button.
For your information, you can choose VP8 or VP9 for the WebM option. VP9 outperforms VP8 on compression ratio but VP8 is more compatible with diverse browsers.
Please be sure to check your WebM video on the system where it will be played because there are some browsers that do not support WebM.
Please be careful! Most video players do NOT support videos with transparent backgrounds! Even the Windows File Explorer can NOT show transparent WebM correctly.
Please use Honeycam or web browsers like Chrome, Firefox, or Safari to see transparent WebM videos correctly.