How to Export Video with Transparent Background in After Effects

Great question — exporting with transparency is one of the most common needs in motion design, especially for overlays and lower thirds.

The key concept: You need a format that supports an alpha channel (the transparency data). Not all formats do — MP4/H.264 does NOT support transparency.

Method 1: QuickTime with Alpha (Recommended)
1. Add your comp to the Render Queue (Composition → Add to Render Queue)
2. Click "Lossless" next to Output Module
3. Set Format to QuickTime
4. Click Format Options → set codec to Apple ProRes 4444 (or Animation)
5. Under "Channels" dropdown, select RGB + Alpha
6. Click OK and Render

Method 2: PNG Sequence
1. Output Module → Format: PNG Sequence
2. Channels: RGB + Alpha
3. This creates individual frames — great for quality, but you'll need to reassemble in your editor

Method 3: Via Media Encoder
1. Composition → Add to Adobe Media Encoder Queue
2. Choose QuickTime → ProRes 4444 with Alpha

Pro tip: Make sure your composition background is actually transparent — if you see a checkerboard pattern when you toggle the transparency grid (the ⊞ button at the bottom of the comp viewer), you're good. If you see a solid color, your background isn't transparent.

Common mistake: Rendering to H.264/MP4. This format doesn't support alpha channels, so your background will render as black or the comp background color.