Similar to my post on scripting, this is intended to be a roundup of a bunch of resources for learning javascript-based After Effects expressions. I'm focusing less on specific tutorials and more on broader-picture materials.

Like scripting, AE expressions are based on Javascript. However, as of AE 16.0+ (CC2019), AE now has a new expression engine that lets you use modern Javascript, not just the ancient ExtendScript system!

If you're looking for ways to manage and store your expressions, I've got another post all about that. I also wrote about some unexpected and typically unexplored facets of the Expression Flyout Menu for School of Motion.

Looking for scripting resources? Check out this post!

I want to point out that this isn't an exhaustive list– there's a lot of information out there! This is solely a roundup of links that I can personally vouch for and have appreciated. Have more to add? Reach out!

Learning Javascript

• Eloquent Javascript, by Marijn Haverbeke
• Javascript Pocket Reference, by David Flanagan
• Javascript: The Good Parts, by Douglas Crockford

Free Training

• Workbench
  • Workbench is amazing. Joe is amazing. This is all great.
• Animoplex - World of Expressions
  • Super comprehensive!
• MotionScript - AE Expressions
  • Old school cool
• Ukramedia: Expressions Tutorials

Paid Training

• School of Motion: Expression Session (I taught this one!)
• fxphd: After Effects Expressions Bootcamp
• Ukramedia: Learn After Effects Expressions 1.0
• AE Expressions courses on Skillshare

Reference Materials

• Docs for Adobe AE Expressions Reference
  • This is based on the official link below, but with a bunch more community-driven content and specific caveats or use cases noted.
• Adobe Expression Language Reference
  • Straight from the horse's mouth!

Discussion Boards

• Adobe Forums: AE Expressions
  • Classic.
• aenhancers Expressions Forum
  • Old old forum with very infrequent posts, but a lot of pertinent, still-relevant data here.