Acorn

Tiny, fast JavaScript parser for efficient code analysis and transformation.

EstablishedOpen SourceLow lock-in

Pricing

Free tier

Flat rate

Adoption

Stable

License

Open Source

Data freshness

Verified · Jul 12, 2026

Overview

What is Acorn?

Acorn is a lightweight and high-performance JavaScript parser that enables developers to parse and analyze JavaScript code efficiently. It's ideal for projects requiring minimal overhead and rapid parsing capabilities.

Key differentiator

Acorn stands out as one of the fastest and most lightweight JavaScript parsers available, making it an ideal choice for developers who need efficient parsing without additional overhead.

Capability profile

Capability Radar

Ease of StartEcosystemValueMaturityFlexibilityScale Ready

Honest assessment

Strengths & Weaknesses

↑ Strengths

Minimal overhead and fast parsing speedmedium

Extensive documentation and community supportmedium

Flexible configuration options for custom parsing needsmedium

↓ Weaknesses

Limited support for the latest ECMAScript featureshigh

Acorn may not fully support the most recent JavaScript language updates, leading to parsing errors with newer codebases.

Lack of built-in transformation capabilitiesmedium

While Acorn can parse JavaScript effectively, it does not provide tools for transforming or modifying the Abstract Syntax Tree (AST), which may require additional libraries like ESTree.

Configuration complexity for custom parsing needshigh

Customizing Acorn to meet specific project requirements can be complex and error-prone, especially when dealing with advanced options or edge cases in JavaScript syntax.

Fit analysis

Who is it for?

✓ Best for

Developers working on projects that require efficient and lightweight JavaScript parsing

Teams building tools that need to analyze or transform JavaScript code without significant overhead

✕ Not a fit for

Projects requiring extensive support for multiple programming languages beyond JavaScript

Applications needing a full-fledged development environment with integrated debugging capabilities

Cost structure

Pricing

Free Tier

Available

Open source — free to use

Starts at

$0

Model

Flat rate

Enterprise

None

Performance benchmarks

How Fast Is It?

Ecosystem

Relationships

Next step

Get Started with Acorn

Step-by-step setup guide with code examples and common gotchas.

View Setup Guide →