About Esprima

High-performance JavaScript parser for modern web development

Try the parser • Read documentation • View examples

What is Esprima?

Esprima is a high-performance, standards-compliant ECMAScript parser written in ECMAScript. It was created by Ariya Hidayat in 2011 and has since become one of the most widely used JavaScript parsers in the ecosystem.

The parser is designed to be fast, accurate, and easy to use. It produces an Abstract Syntax Tree (AST) that follows the ESTree specification, which has become the de facto standard for JavaScript AST formats.

Core Philosophy

Esprima was built with several key principles in mind:

  • Standards Compliance: Fully compliant with ECMAScript specifications
  • Performance: Optimized for speed without sacrificing accuracy
  • Simplicity: Clean API that's easy to understand and use
  • Reliability: Extensively tested with comprehensive test suites

Technical Specifications

ECMAScript Support

Supports ECMAScript 2020 (ES11) including all major language features like classes, modules, arrow functions, async/await, and more.

AST Format

Produces AST following the ESTree specification, ensuring compatibility with other tools in the JavaScript ecosystem.

Location Tracking

Optional source location tracking for every node, useful for error reporting and source maps.

Token Information

Can extract detailed token information for lexical analysis and syntax highlighting.

Real-World Applications

Esprima powers many popular tools and frameworks in the JavaScript ecosystem:

Code Analysis Tools

ESLint and other linters use Esprima to analyze code quality and enforce coding standards.

Build Tools

Webpack and other bundlers leverage Esprima for module analysis and dependency resolution.

Code Transformation

Babel and other transpilers use AST parsing for code transformation and compatibility.

Documentation Generators

Tools like JSDoc use Esprima to parse JavaScript and generate documentation.

Performance Characteristics

Esprima is designed for performance. It can parse large JavaScript files quickly and efficiently:

  • Single-pass parsing algorithm
  • Minimal memory footprint
  • Optimized for modern JavaScript engines
  • No external dependencies

Start Using Esprima

Ready to parse JavaScript code? Try our online parser or integrate Esprima into your project.

Try Parser Read Documentation