About placeholders and proxies

When you want to temporarily use a substitute for footage, choose one of two alternatives: a placeholder or a proxy.

Placeholder

A still image of color bars used to temporarily take the place of missing footage. Use a placeholder when you are building a composition and want to try out ideas for footage that is not yet available. After Effects generates placeholders automatically, so you do not have to provide any placeholder footage.

Proxy

Most often a lower-resolution or still version of existing footage used to replace the original to save processing time. Use a proxy when you have the actual footage but you want to speed up previewing or rendering of test movies. You must have a file available to use as a proxy.

Using either method, any attributes and keyframes you apply to the placeholder or proxy are transferred to the actual footage when you insert it. You can even set a proxy for a placeholder, so that you use a low-resolution or still version of full-resolution footage that is not yet available. (See Working with missing source footage and Substituting a low-resolution proxy for footage.)

If final footage is unavailable, and you simply want to substitute draft footage or a storyboard still image, you can import the draft footage and replace it with final footage later.