Which video format
keeps transparency?
For MographAI lower thirds, use transparent WebM or ProRes 4444 MOV. The MP4 news export is an opaque, finished composition. Transparency depends on the codec, pixel data and the software opening the file—not just its extension.
| Export | MographAI use | Check before choosing |
|---|---|---|
| MP4 / H.264 | Finished news clip | Does not preserve an alpha background in this tool. |
| WebM / VP8 | Reusable transparent lower third | The receiving editor must support WebM alpha. |
| MOV / ProRes 4444 | Reusable transparent lower third | Larger files; requires a compatible desktop editing workflow. |
What is an alpha channel?
An alpha channel describes how transparent a pixel is. Fully transparent pixels let the video beneath show through. Intermediate values preserve soft edges and shadows. A checkerboard is just a way for editing software to display this empty area; it should not become part of the exported graphic.
How to test a downloaded overlay
- Put an unrelated video or a bright solid background on the lower track of a compatible editor.
- Place the downloaded lower third above it.
- Play the entrance, middle and exit. Look for a solid rectangle where empty space should be.
- Inspect the text edges and shadow. A black preview in a standalone player alone does not establish that alpha is missing.
Why doesn’t every MOV work?
MOV is a container. MographAI specifically uses ProRes 4444 for its alpha-capable MOV export. Other MOV codecs can behave differently. Likewise, not every WebM file contains alpha. Ask about the actual codec and transparency settings, not only the filename.
What has MographAI tested?
The original local pipeline was tested by decoding alpha planes and compositing over synthetic moving footage. The public browser export path has also passed separate MP4, WebM and ProRes export and alpha-decoding checks. Target-editor compatibility varies; a successful browser download is not a claim that every editing application can import it.
Technical references: MDN’s media container guide, FFmpeg codec documentation.
Make a transparent lower thirdBy SupaMakers · Reviewed September 9, 2026