Why does my exported video lose transparency and turn black?
Transparency turns black when the file never stored an alpha channel or when the app ignores it. The usual causes are exporting H.264 MP4, choosing ProRes 422 instead of ProRes 4444, an editor that interprets the clip as opaque, or a player that composites onto black. Re-export as ProRes 4444 MOV for editors or VP9 WebM for web and OBS, then check the pixel format before importing.
Updated
Why does my transparent video have a black background?
Same problem, asked from the file you already downloaded. Black was often written into an MP4 on export. That is opaque pixel data, not a hidden alpha channel you can switch on.
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Where it turns black
| Where it turns black | Likely cause | Fix | Source |
|---|---|---|---|
| Premiere Pro export | H.264, or a ProRes profile other than 4444 / 4444 XQ | QuickTime and ProRes 4444 with an alpha depth. Labels move between Adobe versions. | Premiere guide. Apple: only 4444 and 4444 XQ carry alpha. |
| After Effects | Alpha interpreted as ignore, or a premultiply mismatch. A player may also show leftover green. | Interpret Footage, Alpha: Straight - Unmatted. Put a solid color underneath. | After Effects guide, citing Adobe's footage interpretation page. |
| DaVinci Resolve | The clip is treated as opaque, or the export codec has no alpha. | Export a codec that stores alpha, such as ProRes 4444, and test over a colored layer. Public docs for some apps conflict. | Do not follow an unverified click path. Test the file. |
| Final Cut Pro | A ProRes flavor with no alpha | ProRes 4444 or 4444 XQ | Apple ProRes support |
| OBS | The file is MP4, a chroma key was added, or the source is a window capture of a player | Media Source and a WebM that already has alpha. Remove the chroma key. | OBS Media Sources |
| Browser | Safari plus WebM alpha | Not black. WebKit bug 275908 says a grey background. Use an HEVC-with-alpha source for Safari. ExportAlpha does not create that file. | WebKit 275908 |
| System player (QuickTime, VLC, and similar) | The player composites transparency onto black | Not a file error by itself. Verify in an editor or in Chrome over a colored page. | Playback behavior, not a codec spec |
ProRes: which profiles have alpha
Apple's support page says ProRes 4444 and ProRes 4444 XQ are the only Apple ProRes codecs that support alpha channels. 422 HQ, 422, 422 LT, and 422 Proxy do not. ExportAlpha's ProRes export is ProRes 4444 and is limited to 8 seconds. Longer clips should be WebM.
Safari is grey, not a second kind of black
Chrome and Firefox can composite VP9 WebM alpha. On October 9, 2026, Chromium 140 played a yuva420p WebM over a magenta page and the page color showed through. Safari is the WebKit bug, not that Chromium result. Bug 275908 (status NEW the same day) says a grey background rather than transparent.
Playwright WebKit 26.0 on Linux crashed when a video element was given a source, so this site still has not watched macOS Safari paint the frame. Linux WebKit is not macOS Safari. iOS WebM alpha is not verified. Delivery for both browsers is transparent video for Safari and Chrome. The older Safari write-up is Why is my transparent WebM black in Safari?.
How to verify
For a WebM made with the commands on the MP4 to transparent WebM page:
ffprobe -v error -select_streams v:0 -show_entries stream=pix_fmt:stream_tags=alpha_mode -of default output.webm
ffmpeg -hide_banner -c:v libvpx-vp9 -i output.webm -f null -Look for alpha_mode=1 in the first command and yuva420p in the second. ProRes 4444 from an editor is a different pixel format, often yuva444p10le. Then layer the clip over a solid color in Premiere, After Effects, Resolve, or Final Cut.
Frequently Asked Questions
Why does my transparent video have a black background?
Black usually means the file never stored an alpha channel, or the app you opened ignores the alpha and composites onto black. H.264 MP4 does not support transparency. Chrome can composite WebM alpha. Safari plays WebM and, per WebKit bug 275908, shows a grey background rather than transparency.
Can you fix alpha on an MP4 that already has black built in?
No. Black built into the MP4 is opaque pixel data. Re-export from a source that still separates the subject, or run background removal, then write WebM or ProRes with alpha.
How do I check if my video has an alpha channel?
On FFmpeg 6.1.1, ffprobe of a VP9 WebM with alpha reported pix_fmt yuv420p and the tag alpha_mode=1. Decoding with -c:v libvpx-vp9 reported yuva420p. Also import the file into an editing timeline and layer it over a colored background.
What should I do if my transparent video appears black?
For Chrome, Firefox, and OBS, export transparent WebM. For editing, export ProRes 4444 MOV. For a Safari web page, use HEVC-with-alpha from an encoder that writes it. Do not export everyday H.264 MP4 if you need transparency. ExportAlpha does not export HEVC-with-alpha.
Why does my video look correct in Chrome but wrong in Safari?
Chrome composited VP9 alpha in a Chromium 140 test on October 9, 2026: a magenta page showed through the transparent pixels. Safari is a different case. WebKit bug 275908 says the same kind of file plays with a grey background rather than transparent. A Linux Playwright WebKit build crashed when any video source was set, so that test did not measure grey or black, and it is not macOS Safari.
Why is my ProRes still black in Premiere?
ProRes 422, 422 HQ, 422 LT, and 422 Proxy do not carry alpha. Apple says only ProRes 4444 and ProRes 4444 XQ support alpha channels. Export QuickTime with ProRes 4444 and an alpha depth. A desktop player that paints black is not the Premiere test. Put a colored layer under the clip.
Why does my clip look green instead of transparent?
Everyday players often keep leftover green because they ignore alpha. Import the ProRes MOV in After Effects, interpret Alpha as Straight - Unmatted, and place a solid color underneath. A green thumbnail is not proof the export failed.
Does re-exporting the black MP4 bring transparency back?
No. Re-encoding an opaque MP4 copies the black pixels. You need a source that still has a separate subject and background, or a new matte from background removal.
Sources
- Apple ProRes alpha: support.apple.com/en-us/102207 (retrieved October 9, 2026). "They are also the only Apple ProRes codecs that support alpha channels."
- WebKit bug 275908: grey background rather than transparent (status NEW, retrieved October 9, 2026).
- After Effects alpha interpretation: Interpreting footage items.
- OBS Media Sources: Official KB (retrieved October 9, 2026).
Export your video with real alpha
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Related guides
- Remove a video background and keep it transparent
- Convert an MP4 with a solid background to transparent WebM
- Transparent video for Safari and Chrome
- Transparent overlay in OBS
- Export a transparent video from After Effects
- Export a transparent video from Premiere Pro
- Does MP4 support a transparent background?
- Which video formats support transparency?