How to Export a Transparent Video with an Alpha Channel (ProRes 4444)
An MP4 can't hold transparency, so a lower third or a cut-out character exported the usual way lands on black. This is which formats carry alpha, the export settings in each app from the vendors' own docs, tested ffmpeg commands, and how to check a file really has its alpha before it goes to the editor.
To export a video with a transparent background, render it to a format that stores an alpha channel: ProRes 4444 in a .mov for editing apps, VP9 WebM for the web, or a PNG image sequence. Then make sure the export actually writes the alpha. An H.264 MP4 never keeps it, so the transparent areas come out black.
Which formats carry alpha
Transparency is a fourth channel stored next to the color in every pixel. A format either has room for it or it does not.
| Format | Alpha | Typical use | What to watch |
|---|---|---|---|
| ProRes 4444 (.mov) | Yes, up to 16-bit, lossless | Handing graphics and cut-outs to an editor or compositor | Large files |
| ProRes 4444 XQ (.mov) | Yes, up to 16-bit, lossless | The same, at a higher data rate for high dynamic range work | Larger still |
| ProRes 422, 422 HQ, LT, Proxy | No | Editing and masters | Transparency is flattened |
| VP9 WebM (.webm) | Yes | Transparent video on web pages | Not every editing app reads its alpha |
| PNG sequence | Yes | Frame-by-frame handoff between apps | Thousands of files, no audio |
| H.264 or HEVC MP4 | No | Delivery, social, streaming | Alpha is dropped on export |
The ProRes rows come from Apple's ProRes white paper (April 2022), which says ProRes 4444 XQ and 4444 "are the only ProRes codecs that support alpha channels." Picking ProRes 422 HQ because it is the usual master format is the most common way a transparent export ends up opaque. If ProRes itself is new to you, start with what Apple ProRes is and how the flavors differ.
Why ProRes 4444 is the editor's default
Apple encodes the alpha in ProRes 4444 differently from the picture. The color is "visually lossless", meaning compressed in a way you should not see, while the alpha is mathematically lossless at any bit depth up to 16 bits. Alpha values control blending rather than being a picture to look at, so Apple stores them exactly: every soft edge and motion blur in the matte decodes to the values you exported.
Apple also says an alpha channel "typically results in only a small increase" in data rate, because a matte is mostly flat areas plus outlines, and that it costs about 10 percent or less in encoding and decoding speed.
The price is file size. Apple's target rate for ProRes 4444 at 1920x1080 and 29.97 fps is about 330 Mb/s, before alpha:
- 330 / 8 = 41.25 MB per second
- 41.25 x 60 = 2,475 MB, about 2.5 GB per minute
Fine for a ten second lower third, heavy for a ten minute overlay. VP9 WebM is far smaller, but for a file going into an edit, ProRes 4444 is what Apple calls ideal for exchanging motion graphics media, and it opens in every app below.
How to export with alpha in each app
Settings move between versions, so each section below is dated to the vendor page we checked.
Final Cut Pro
As of Final Cut Pro 12.4 (Apple's user guide, checked November 2026):
- Select the project or clip, then choose File > Share > Export File (Command-E).
- Click Settings at the top of the Share window.
- Set Format to a mastering format (Video and Audio, or Video Only if there is no sound).
- Set Video Codec to Apple ProRes 4444. Apple notes that the codec choices depend on the project's media format.
To check it, Apple's guide on alpha channels shows the test itself: put the exported file over another clip with Edit > Connect to Primary Storyline (Q). If the background shows through where it should, the alpha is there.
Premiere Pro
Adobe's supported-formats page (updated September 30, 2026) lists Apple ProRes support on macOS and Windows. In the Export settings, choose QuickTime as the format and Apple ProRes 4444 as the video codec. Adobe's export reference (updated August 18, 2026) says ProRes exports need "Render at Maximum Depth" turned on to reach the extra Export Color Space options.
Two things in Adobe's docs are easy to confuse with a transparent export:
- Render Alpha Channel Only renders the matte itself as a grayscale video. Adobe describes it as useful for formats like MXF "that don't support transparency info". It gives you a separate matte file, not a transparent one.
- Transparency in the export settings applies to animated GIF only.
Adobe's reference pages do not describe a separate transparency switch for QuickTime exports, so check the file before you send it (see the ffprobe step below).
After Effects
As of Adobe's "Basics of rendering and exporting" page (updated March 27, 2026), alpha is set in the Output Module of the Render Queue:
- Add the composition to the Render Queue and click the Output Module settings.
- Choose QuickTime and the Apple ProRes 4444 codec.
- Set Channels to RGB+Alpha. Adobe says this produces a movie with an alpha channel, "implying a depth of Millions of Colors+", and warns that not all codecs support alpha.
- Set Color to Premultiplied (Matted) or Straight (Unmatted), whichever the app receiving the file expects.
If edges look dark or haloed after import, the receiving app is usually reading the alpha with the wrong interpretation. Match the setting on both ends.
DaVinci Resolve
The DaVinci Resolve 20 reference manual (chapter 50, Compositing and Transforms in the Timeline) says alpha channels "can be rendered back out" if you choose a Format and Codec combination that supports alpha output "and turn on the Export Alpha checkbox in the Video panel of the Render Settings list." On the Deliver page that means a combination such as QuickTime with Apple ProRes 4444, with Export Alpha checked. The same checkbox appears in VFX Connect when sending clips to Fusion.
Doing it with ffmpeg
ffmpeg is handy for a PNG sequence from a 3D or motion app, or for batch conversion. We ran each command below on a 3 second 1920x1080, 24 fps test clip with a transparent background and checked the output with ffprobe.
A PNG sequence with alpha to ProRes 4444:
ffmpeg -framerate 24 -i frame_%04d.png -c:v prores_ks -profile:v 4 -vendor apl0 -pix_fmt yuva444p10le -alpha_bits 16 cutout_4444.mov-profile:v 4 selects 4444, the yuva pixel format keeps the alpha plane, and -alpha_bits 16 stores it at full depth. Without the a in the pixel format the alpha is thrown away.
ProRes 4444 to VP9 WebM for a web page:
ffmpeg -i cutout_4444.mov -c:v libvpx-vp9 -pix_fmt yuva420p -crf 30 -b:v 0 cutout.webmTo check any file before it leaves your hands:
ffprobe -v error -select_streams v:0 -show_entries stream=codec_name,codec_tag_string,profile,pix_fmt -of default=noprint_wrappers=1 cutout_4444.movFor our test file it printed codec_name=prores, profile=4444, codec_tag_string=ap4h and a yuva pixel format. The a in yuva is the alpha plane; yuv422p10le or yuv444p10le means there is none. The decoded matte matched the source PNGs exactly. For the WebM, ffprobe shows yuv420p but a tag alpha_mode=1, because VP9 stores alpha as a side stream; the libvpx-vp9 decoder returns the full matte.
Converting that same 4444 file to H.264 with libx264 gave a file with no alpha plane at all, with no warning. That is how transparent graphics end up on black.
One caveat from Apple: its white paper names FFmpeg among unauthorized ProRes implementations that "may lead to decoding errors" and incompatibility. When a delivery spec asks for an authorized encoder, export from an app on Apple's licensed list.
When the clip didn't start with transparency
The exports above only work if the transparency already exists: a title, a 3D render, a graphic on an empty layer. Live footage or an AI-generated clip has a real background in every frame, so it has to be cut out first.
Treza's video background remover does that cut. Upload a clip in chat and ask for the background removed, or put the Remove Video Background node in a pipeline, and pick the output: ProRes 4444 (.mov) or VP9 WebM keep a real alpha channel, MP4 puts the subject on black, and GIF is offered too. Models are tuned for general footage, people (Portrait) or fine edges like hair and fur (Matting). Footage shot on green gets the green spill taken off thin edges, so whiskers and hair do not show as green lines over your plate. Every run also returns the black and white mask it used. Sound is not carried through the cut, so lay the original audio back in the edit.
For a subject that does not exist yet, ask the AI video generator in chat for a character, mascot or product "with a transparent background". It renders the subject on a flat chroma green screen and then cuts it out to a transparent ProRes 4444 MOV as soon as it lands. The video model itself outputs an ordinary H.264 MP4; the ProRes 4444 comes from that cut-out step.
For many clips, an AI video pipeline chains generation and background removal so each one arrives as a transparent .mov.
Frequently Asked Questions
Does ProRes 4444 have an alpha channel?
It can. ProRes 4444 and 4444 XQ are the only ProRes codecs that support alpha, stored mathematically lossless at up to 16 bits. The alpha is optional, so a 4444 file only has one if the export wrote it; check with ffprobe for a yuva pixel format.
How do I export a video with a transparent background?
Render to a format with an alpha channel, turn on the app's alpha setting, and export. In practice that is QuickTime with Apple ProRes 4444 for editing apps, with RGB+Alpha in After Effects or Export Alpha in DaVinci Resolve, or VP9 WebM for a web page.
Can an MP4 file have a transparent background?
Not the H.264 MP4s that apps, phones and AI video models produce. Exporting a transparent timeline to H.264 fills the empty areas with black. For transparency, use ProRes 4444 in a .mov, VP9 WebM or a PNG sequence.
What is the best format for transparent video?
It depends where the file goes. For an editor or compositor working in Premiere, Resolve, Final Cut or After Effects, ProRes 4444 is the usual handoff, and Apple describes it as ideal for exchanging motion graphics. For a website, VP9 WebM keeps alpha at a fraction of the size. A PNG sequence works between almost any apps but has no audio.
Why does my transparent video have a black background?
Either the format cannot hold alpha (H.264 MP4, any ProRes 422 flavor), the alpha setting was off, or the player ignores alpha and shows black. Put the file over another clip in your editor to see whether the transparency is there.
Should I export straight or premultiplied alpha?
Use what the receiving app expects. Both store the same transparency but differ in how color is stored at soft edges. Dark edges or a fringe after import mean the alpha is being read the wrong way: change the interpretation in the receiving app or re-export with the other option.
