Often I'll get asked about how you can learn After Effects scripting; what sites, resources, reference materials are great for learning from.

After giving the same set of links every time, I wanted to collect them all in a single place that I'll try to keep up to date.

A few things to note:

• ExtendScript, the language that Adobe scripts are written in, is a version of Javascript. This means that a lot of the time, you can look up general Javascript reference materials or posts online. However! ExtendScript uses a reaaaaally old version of Javascript, as ExtendScript hasn't kept up with 20 years worth of Javascript development. Still-- the foundations are shared.
• 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!

Looking for After Effects expressions resources? Check out this post!

Learning Javascript

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

Free Training

• Pro Video Coalition - AE ExtendScript Training Complete Series
  • Fairly straightforward, low-level training series to teach foundational tasks.
  • While I'm not the biggest fan of the coding style or some of the structure decisions here, as a primer it's pretty good!
• MotionScript - AE Scripting
  • Not a lot here, but every step is very elegantly broken down in a tried, trusted Dan Ebberts way. A keystone in After Effects nerdery.

Paid Training

• fxphd: Scripting in AE
  • Great, thorough, hand-holding first steps to understanding scripting within AE.
• fxphd: Advanced Scripting for After Effects (Part 1, Part 2)
  • Springboarding off the above, these go further and teach things like version control, build systems, using libraries or other dependencies in your tools.
  • Great for taking it to the next level!

Reference Materials

• Docs for Adobe ExtendScript Reference Guide
  • Online, up-to-date, community-driven guide for ExtendScript itself (shared across all host apps).
• Docs for Adobe AE Scripting Guide
  • Online, up-to-date, community-driven AE scripting guide.
• ScriptUI for Dummies Guide
  • This doc gives a whole lot of useful tips, tricks, and walkthroughs for constructing UIs using ExtendScript's ScriptUI system.
• Redefinery
  • Jeff Almasol works at Adobe! Creator of a tonne of very helpful, everyday tools. Best part? They're open source! Being able to break down his scripts was a huge help in my own trying to learn how to write scripts.

Discussion Boards

• Adobe Forums: AE Scripting
  • Classic.
• aenhancers Forum
  • Old old forum with very infrequent posts, but a lot of pertinent, still-relevant data here.
• Stack Overflow ("extendscript" tag)
  • A huge programming help site; this link is focused on posts tagged with ExtendScript.

Wondering how I actually write my scripts? I've written about how I use Visual Studio Code, as well as some tricks on how I (used to) use the official Extendscript Debugger Toolkit.