Moo vs PEG.js

Side-by-side — pricing, strengths, tradeoffs, and fit.

Moo

Optimized tokenizer/lexer generator for high performance.

PEG.js

Simple parser generator for JavaScript with fast parsers and excellent error reporting.

At a glance

Open SourceFree Tier
● Established·From $0
Open SourceFree Tier
◌ Declining·From $0

Overview

One-liner

Optimized tokenizer/lexer generator for high performance.

One-liner

Simple parser generator for JavaScript with fast parsers and excellent error reporting.

Maturity

Established

Maturity

Declining

Open source

✓ Yes

Open source

✓ Yes

Pricing

Free tier

✓ Available

Open source — free to use

Free tier

✓ Available

Open source — free to use

Starts at

$0

Starts at

$0

Model

Flat rate

Model

Flat rate

Enterprise

✕ None

Enterprise

✕ None

Best for

✓ Best for

JavaScript developers working on projects with heavy text processing requirements who need a fast and efficient tokenizer/lexer generator.
Projects where performance is critical and custom tokenization rules are necessary.
Developers building parsers, compilers, or other applications that require high-speed lexing operations.

✓ Best for

JavaScript developers who need to parse complex grammars efficiently and with clear error messages.
Projects requiring custom syntax parsing, such as DSLs or configuration files.

Not ideal for

✕ Not for

Projects requiring real-time streaming capabilities (Moo is optimized for batch processing).
Applications where the overhead of setting up a tokenizer/lexer generator outweighs the benefits.

✕ Not for

Scenarios where a full-fledged parser generator like ANTLR is required due to its more extensive feature set.
Real-time data processing tasks that require extremely low latency and high throughput.

Strengths

↑ Strengths

High-performance tokenization and lexing capabilities.
Optimized for speed and efficiency in text processing tasks.
Flexible configuration options for customizing tokenizer behavior.

↑ Strengths

Generates fast parsers from PEG grammars
Provides excellent error reporting for easier debugging
Simple and easy to use API
Supports JavaScript ES6+ features

Weaknesses

↓ Weaknesses

Complex setup and configuration
Poor documentation for advanced use cases

↓ Weaknesses

Limited integrations with other ecosystems
Complex setup for non-trivial grammars
Performance issues with large input sizes
Documentation lacks depth for advanced use cases
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