Esprima (, BSD license) is a high performance, standard-compliant ECMAScript parser written in ECMAScript (also popularly known as JavaScript). Esprima is created and maintained by Ariya Hidayat, with the help of many contributors.


  • Full support for ECMAScript 5.1 (ECMA-262)
  • Sensible syntax tree format compatible with Mozilla Parser AST
  • Optional tracking of syntax node location (index-based and line-column)
  • Heavily tested (> 600 unit tests with solid statement and branch coverage)
  • Experimental support for ES6/Harmony (module, class, destructuring, ...)

Esprima serves as a building block for some JavaScript language tools, from code instrumentation to editor autocompletion.

Esprima runs on many popular web browsers, as well as other ECMAScript platforms such as Rhino and Node.js.

For more information, check the web site