CmpStr – Modern String Similarity Package

CmpStr is a modern TypeScript library for advanced string comparison, similarity measurement, phonetic indexing, and text analysis. It provides a comprehensive collection of established algorithms such as Levenshtein, Dice–Sørensen, Jaro-Winkler, LCS, q-Gram, and more.

The library is dependency-free, fully typed, and designed with extensibility in mind. Custom metrics, phonetic mappings, normalization filters, and processing pipelines can be integrated without modifying the core. CmpStr offers a unified, consistent API for single comparisons, batch processing, and pairwise matching across synchronous and asynchronous workflows.

Originally released in 2023 with a minimal feature set, CmpStr was fundamentally redesigned in 2025 to support a broader range of algorithms, scalable processing, and more demanding real-world use cases.

Key Features

• Unified API for string similarity, distance measurement, and matching
• Modular metric system with built-in support for 11 different metrics
• Integrated phonetic algorithms (e.g. Soundex, Metaphone) with a configurable registry
• Configurable normalization and filtering pipeline for consistent input processing
• Single, batch, and pairwise comparisons with structured, type-safe results
• Structured data comparison via property extraction
• Utilities for text structure and readability analysis (e.g. syllables, word statistics)
• Diffing utilities with CLI-friendly output formats
• TypeScript-native design with full type declarations
• Optional asynchronous API for scalable, non-blocking workloads
• Extensible architecture for custom algorithms, processors, and filters

Getting Started

Install CmpStr using npm:

npm install cmpstr

or with yarn:

yarn add cmpstr

Minimal Example

import { CmpStr } from 'cmpstr';

const cmp = CmpStr.create().setMetric( 'levenshtein' ).setFlags( 'i' );
const result = cmp.test( [ 'hello', 'hola' ], 'Hallo' );

console.log( result );
// { source: 'hello', target: 'Hallo', match: 0.8 }

Asynchronous Usage

import { CmpStrAsync } from 'cmpstr';

const cmp = CmpStrAsync.create().setProcessors( {
  phonetic: { algo: 'soundex' }
} );

const result = await cmp.searchAsync( 'Maier', [
  'Meyer', 'Müller', 'Miller', 'Meyers', 'Meier'
] );

console.log( result );
// [ 'Meyer', 'Meier' ]

Try it online with OneCompiler.

CLI Tool

CmpStr can also be used directly from the command line via cmpstr-cli. The CLI exposes many of the library’s features for interactive use, scripting, and automated processing, making it suitable for data cleaning, analysis, and batch workflows.

Documentation

Comprehensive documentation, API references, and advanced usage examples are available in the GitHub Wiki.

Check out the technical documentation created with TypeDoc, which exposes all classes, methods and types.

License

MIT License — © 2023–2026 Paul Köhler (komed3)