I've submitted an answer for this on the main StackOverflow site - pasted below for context
I've need to do this myself a few times - especially when installing on another machine.
Depending on your platform, your extensions folder is located on one of the following paths:
- Windows:
%USERPROFILE%\.vscode\extensions
- Mac:
~/.vscode/extensions
- Linux:
~/.vscode/extensions
VS Code looks for extensions under your extensions folder .vscode/extensions. Depending on your platform it is located: Windows %USERPROFILE%.vscode\extensions Mac ~/.vscode/extensions Linux ~/.vscode/extensions That should show you a list of the extensions
I've also had success using Visual Studio Code Settings Sync Extension to sync settings to GitHub gist
EDIT: In the lastest release of VSCode (May 2016) it is now possible to list the installed extension in the command line
code --list-extensions