Convert ProRes 4444 → WebM — free
The H.264 trap
Most Premiere timelines end as an H.264 MP4, so that is the export everyone reaches for — and it is the one export that can never work here. H.264 and HEVC have no alpha channel in any container they ship in; no preset, no checkbox, no bitrate setting adds one. MP4 simply does not support transparency.
So the choice is between two alpha-carrying routes: a ProRes 4444 QuickTime for editing and archiving, or a VP9-alpha WebM for web pages and OBS.
Route 1: ProRes 4444 (the reliable one)
- In Premiere, choose File → Export → Media with your sequence selected, or send the job to Adobe Media Encoder's queue.
- Set the format to QuickTime and the video codec to Apple ProRes 4444. Current versions of Premiere and Media Encoder export ProRes on Windows as well as macOS.
- Check the codec carefully: 4444 carries alpha, the 422 variants do not. This is the single most common wrong pick.
- Export. When the sequence contains transparency, the alpha channel is included automatically — there is no separate switch to enable.
The result is a .mov master that Premiere, After Effects, Resolve and Final Cut all composite correctly — the import guide covers how each editor expects alpha footage. If the final destination is a website or OBS, run the master through the ProRes → WebM converter afterwards; it is free with a Google sign-in.
Route 2: alpha WebM
Premiere has no built-in WebM export. Two ways around that:
- The WebM plugin. The free third-party WebM plugin for Adobe apps has long added VP8/VP9 export with alpha to Media Encoder. Check that it supports your app version before relying on it in a paid pipeline.
- Convert instead. Export the ProRes 4444 master from Route 1, then use the free ProRes → WebM converter on this site. Same result, no plugin to maintain.
Route 3: PNG sequence
When the next tool in the chain is not a video editor at all — a game engine, a web animation, a frame-by-frame workflow — File → Export → Media with the format set to PNG and sequence export enabled writes every frame as a transparent PNG. Lossless, and the most portable format there is; the downside is the file count. The video → PNG sequence converter does the same job for an existing file.
Verify before you deliver
Alpha problems are invisible in Premiere's own preview, because the program monitor composites over its background. Before handing the file over, play it over two contrasting backgrounds, or drop it into the free transparency checker — it measures how much of the file is actually transparent, in the browser. The full checklist is in the alpha test guide.
And if the export comes back with a black background where transparency should be, the black background guide narrows down which link in the chain dropped the alpha.
Questions people are asking
Can Premiere Pro export an MP4 with a transparent background?+
No. H.264 and HEVC — the codecs inside MP4 exports — have no alpha channel, in any container. Use a QuickTime with Apple ProRes 4444, a VP9-alpha WebM, or a PNG sequence.
Which ProRes codec should I pick for alpha?+
Apple ProRes 4444 (or 4444 XQ). The 422 variants have no alpha channel at all — picking ProRes 422 is the most common reason a Premiere export comes back opaque.
Does Premiere export WebM natively?+
No. WebM export needs the free third-party WebM plugin for Adobe apps, or you can export a ProRes 4444 master and convert it to VP9-alpha WebM with the free converter on this site.
Why did my export come back with a black background?+
Either the export format cannot carry alpha (H.264, ProRes 422), or the sequence itself no longer contains transparency — for example, an opaque clip or effect sits on top. Test the exported file in the transparency checker, and if the file is fine, check the timeline in Premiere.