In any projects at some point you will need to create a simple video clip or a motion graphics animation with a transparent background so I figured it would be useful to share with a tutorial my best tips on how to make an After Effects transparent background with an alpha channel.

First in order to make a transparent background on your After Effects project or any video you need to have an alpha channel.

My simple definition of alpha channel, a colored image has 3 standard channels red,green,blue, the 4th channel is the alpha which allows you to control the opacity or transparency.

If you are interested in a detailed definition of a what is an alpha channel I got one from below:
The alpha channel is a color component that represents the degree of transparency (or opacity) of a color (i.e., the red, green and blue channels). It is used to determine how a pixel is rendered when blended with another.

The alpha channel controls the transparency or opacity of a color. Its value can be represented as a real value, a percentage, or an integer: full transparency is 0.0, 0% or 0, whereas full opacity is 1.0, 100% or 255, respectively.

When a color (source) is blended with another color (background), e.g., when an image is overlaid onto another image, the alpha value of the source color is used to determine the resulting color. If the alpha value is opaque, the source color overwrites the destination color; if transparent, the source color is invisible, allowing the background color to show through. If the value is in between, the resulting color has a varying degree of transparency/opacity, which creates a translucent effect.

The alpha channel is used primarily in alpha blending and alpha compositing.

How to render an After Effects composition with an alpha channel and transparent background?

Exporting,rendering a video with an alpha channel is actually very straight forward just follow these simple steps below.

Step 1 – Make sure your After Effects Composition has a transparent background
At the bottom of your composition panel on the left of active camera there is a little icon checker box icon after effects checkers icon (Toggle Transparency Grid), click on and off to switch between the checker background or the black background. If you see the checkers board background correctly it means that your composition has a transparent background and you can export your video with the alpha channel.

Toggle Transparency Grid

Step 2 – Add your composition to the Render Queue Window
Make sure the composition is open or selected on the project window
Click on Composition > Add to Render Queue
Shortcut: Control+Command+M (MAC) or Ctrl+M  (PC)

Step 3 – Edit the Output Module Options
Located on the bottom left of you render queue window
– Click on LossLess
– Next to Format click on the drop down and select Quicktime

Video Output
– First click Format Options
– “Video Codec:” drop down should be Animation
– Click OK
– Next to “Channels:” on the drop down Select RGB+ALPHA
– Click OK

After Effects output module settings for Alpha Channel

Step 4 – Rendering
Click the button Render

Step 5 – Verify your After Effects transparent background video
Once your video is rendered, import the video in After Effects or Premiere and add something behind the video to make sure the background is transparent and therefore has the alpha channel included.

Which format/extension support and include an alpha channel?

Base on my research I found a couple of video and image format that include an alpha channel, I organized it in 2 categories
– Video Format (One single File)
– Image Files Sequence (Multiple Images that make a video)

Video File Format / Codec OS Max Alpha Channel Bits
Quicktime Animation MOV MAC/PC 32 Bits
AVI PC 32 Bits
Quicktime GoPro CineForm MAC/PC 12 Bits
Apple Animation MAC 8 Bits
Apple ProRes 4444 XQ MAC 16 Bits
Apple ProRes 4444 MAC 12 Bits
Avid Meridien Compressed MAC/PC 8 Bits
Avid Meridien Uncompressed MAC/PC 8 Bits
Avid DNxHD MAC/PC 10 Bits
Avid DNxHR MAC/PC 12 Bits
Cineon MAC/PC 16 Bits
Image File Format OS Max Alpha Channel Bits
DPX MAC/PC 16 Bits
Maya IFF MAC/PC 32 Bits
OpenEXR MAC/PC 32 Bits
PNG MAC/PC 32 Bits
RLA MAC/PC 32 Bits
RPF MAC/PC 32 Bits
SGI MAC/PC 16 Bits
Targa (TGA) MAC/PC 8 Bits

You know other method to get a transparent background and export an alpha channel in After Effects? Please share it on the comment area below.