How do I use the V8 engine?

The V8 engine was introduced in EmEditor v22.1.0.

  1. Go to Macros | Customize… and open the Options page
  2. Check Use V8 as JavaScript engine and click OK

You can also programmatically specify the engine with this line at the top of your macro:

#language = "v8"


#language = "JScript"

JScript compatibility with V8

Method and property identifiers are case-sensitive in V8, unlike JScript. For example, if you wrote redraw = false, in V8 you will need to fix the case to be Redraw = false.

V8 does not support ActiveXObject, but for commonly used methods, you can use the following methods of the Shell object included in EmEditor macros instead:

Run, FileExists, FolderExists, DeleteFile, DeleteFolder, CreateFolder, GetFileAttributes, and SetFileAttributes.

Web API limitations

Certain Web APIs are unavailable on V8, such as import, fetch, and DOM manipulation.