The short answer: MP4 flattens transparency
An MP4 file is a container, and the codec inside determines what the pixels can store. The overwhelming default is H.264 (AVC), which only encodes red, green, and blue—there is no per-pixel alpha value.
That is why an overlay exported as MP4 shows up with a solid black or white background in your editor: the transparency was discarded at export time, not lost during import. No import setting in Premiere, CapCut, or Resolve can bring it back.
The exception: HEVC with alpha (and why it rarely helps)
There is one real exception: HEVC (H.265) with an alpha layer, which Apple supports in Final Cut Pro and on iPhone screen recordings with transparency. Technically that stream can live in an MP4 or MOV container.
In practice it is an Apple-ecosystem feature. Windows editors, browser-based tools, OBS Studio, and most encoders either cannot produce it or cannot read the alpha layer. If your workflow is not entirely Apple, treating MP4 as a no-alpha format is the safe assumption.
- H.264 in MP4: no alpha channel, ever
- HEVC with alpha: works in Final Cut Pro and Apple apps, unreliable elsewhere
- VP9 (which does support alpha) is delivered in WebM, not MP4, by every mainstream tool
What to use instead: WebM or MOV
For overlays with a transparent background, the two formats that work across editors are WebM (VP9 with alpha) and MOV (typically ProRes 4444). Videohead exports both, so you pick based on your editor rather than fighting the MP4 limitation.
WebM is the lighter option and imports cleanly into CapCut Desktop, DaVinci Resolve, and OBS Studio. MOV is the traditional choice for Premiere Pro and Final Cut Pro pipelines and client deliverables. Not sure which one fits your editor? See our full WebM vs MOV comparison.
Already stuck with an MP4?
If someone handed you an overlay as MP4, the transparency is gone from the file. Your options are to chroma-key the solid background (works, but expect fringed edges on glows, shadows, and semi-transparent elements) or to re-export the original project as WebM or MOV.
If the overlay came from Videohead, there is nothing to salvage manually—open the overlay and export it again with transparency as WebM or MOV. The design stays the same; only the container changes.
Key takeaways
- MP4 with H.264 cannot store an alpha channel—transparency is flattened at export
- HEVC-with-alpha MP4s exist but only work reliably inside the Apple ecosystem
- Export WebM or MOV for transparent overlays; Videohead supports both
- A flattened MP4 can only be rescued by chroma keying or re-exporting the source