leven
Measure string differences with Levenshtein distance algorithm.
Pricing
Free tier
Flat rate
Adoption
↘CoolingLicense
Open Source
Data freshness
Aging · Jun 8, 2026Overview
What is leven?
Leven is a JavaScript library that calculates the difference between two strings using the Levenshtein distance algorithm, useful for applications requiring text comparison and similarity measurement.
Key differentiator
“Leven stands out as a lightweight, efficient JavaScript library specifically tailored for calculating Levenshtein distance, making it ideal for developers looking to integrate basic text similarity metrics into their applications without additional complexity.”
Capability profile
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Honest assessment
Strengths & Weaknesses
↑ Strengths
↓ Weaknesses
Leven only provides Levenshtein distance calculation and lacks advanced features such as fuzzy matching, phonetic algorithms, or semantic similarity measures.
The algorithm's time complexity is O(n*m) where n and m are the lengths of the two strings. This can lead to performance issues when comparing very long texts.
As an open-source project, Leven may not have extensive community contributions or comprehensive documentation, which can hinder troubleshooting and learning.
Fit analysis
Who is it for?
✓ Best for
JavaScript developers who need to implement string distance calculations efficiently and accurately.
Projects requiring text comparison functionalities without the overhead of external dependencies.
✕ Not a fit for
Applications needing more complex natural language processing capabilities beyond simple string comparison.
Scenarios where a full-fledged machine learning library is required for advanced text analysis.
Cost structure
Pricing
Free Tier
Available
Open source — free to use
Starts at
$0
Model
Flat rate
Enterprise
None
Performance benchmarks
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Ecosystem
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Next step
Get Started with leven
Step-by-step setup guide with code examples and common gotchas.