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Comparison guide

Langchain vs Mastra

Side-by-side NPM package comparison

Quick Verdict

Smallest Bundle

Langchain

119.0 KB gzipped

Most Popular

Langchain

2.1M weekly downloads

Best Maintained

Langchain

100/100 maintenance score

Highest Quality

Mastra

80/100 quality score

Overall Pick

Langchain

Best all-around based on popularity, size, maintenance & quality

  1. langchain

    Typescript bindings for langchain

    2.1M weekly downloads · 119.0 KB gzip · Health 85/100

    0
  2. mastra

    cli for mastra

    541.8K weekly downloads · 5.3 MB gzip · Health 90/100

    0

Choosing between Langchain and Mastra? Here's a data-driven comparison based on real npm data — downloads, bundle size, health scores, and more — to help you decide which package fits your project best.

Downloads & Popularity

Langchain leads with 2.1M weekly downloads — roughly 3.9x more. Mastra has 541.8K weekly downloads. Higher download counts generally indicate broader community adoption and a larger ecosystem of tutorials, plugins, and support.

Bundle Size

Langchain has the smallest gzipped bundle at 119.0 KB. Mastra comes in at 5.3 MB. A smaller bundle size means faster page loads, which improves user experience and Core Web Vitals scores.

Health Score Comparison

Mastra has an overall health score of 90/100 (excellent), with strong maintenance, quality, security, popularity scores. Langchain has an overall health score of 85/100 (very good), with strong maintenance, security, popularity scores. Health scores are calculated from maintenance activity, code quality, security posture, popularity, and stability metrics.

When to Choose Each

Choose Langchain if you value large community support, actively maintained, strong security track record. Choose Mastra if you value actively maintained, strong security track record.

Our Verdict

Both Langchain and Mastra are solid choices for JavaScript development. Mastra has the edge in overall health score (90/100), while each package brings unique strengths to the table. Evaluate them based on your project's priorities — whether that's community size, bundle efficiency, or maintenance activity — and choose the one that aligns best with your requirements.

Frequently Asked Questions

Is langchain better than mastra?
It depends on your needs. Langchain has a health score of 85/100 while Mastra scores 90/100. Langchain has more recorded weekly downloads (2.1M). Consider your specific requirements — bundle size, community support, and feature set — to decide which is the better fit.
Which has a smaller bundle size, langchain or mastra?
Langchain has the smaller gzipped bundle at 119.0 KB. A smaller bundle means faster load times for your users, which can positively impact SEO and user experience.
How many developers use langchain vs mastra?
Langchain has more recorded weekly downloads (2.1M). Download counts reflect package installations, not unique developers.
Which is better maintained, langchain or mastra?
Langchain has a maintenance score of 100/100. Langchain scores 100/100 and Mastra scores 100/100 on maintenance.

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