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Ajv vs Yup

Side-by-side NPM package comparison

Quick Verdict

Smallest Bundle

Yup

13.1 KB gzipped

Most Popular

Ajv

251.1M weekly downloads

Best Maintained

Ajv

80/100 maintenance score

Highest Quality

Ajv

50/100 quality score

Overall Pick

Ajv

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

ajv icon

ajv

Extremely Popular

Version 8.18.0

0
79
Good

Another JSON Schema Validator

Weekly Downloads
251.1M
22%
Bundle (gzip)
31.9 KB
Updated
Vulns
0

Health Score Breakdown

Maintenance
80
Popularity
100
Quality
50
Security
100
Stability
70
yup icon

yup

Very Popular

Version 1.7.1

0
67
Good

Dead simple Object schema validation

Weekly Downloads
10.0M
12%
Bundle (gzip)
13.1 KB
Updated
Vulns
0

Health Score Breakdown

Maintenance
40
Popularity
100
Quality
50
Security
100
Stability
70

Choosing between Ajv and Yup? 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

Ajv leads with 251.1M weekly downloads — roughly 25.2x more. Yup has 10.0M weekly downloads. Higher download counts generally indicate broader community adoption and a larger ecosystem of tutorials, plugins, and support.

Bundle Size

Yup has the smallest gzipped bundle at 13.1 KB. Ajv comes in at 31.9 KB. A smaller bundle size means faster page loads, which improves user experience and Core Web Vitals scores.

Health Score Comparison

Ajv has an overall health score of 79/100 (very good), with strong maintenance, security, popularity scores. Yup has an overall health score of 67/100 (good), with strong security, popularity scores. Health scores are calculated from maintenance activity, code quality, security posture, popularity, and stability metrics.

When to Choose Each

Choose Ajv if you value massive community and ecosystem, strong security track record. Choose Yup if you value large community support, strong security track record.

Our Verdict

Both Ajv and Yup are solid choices for JavaScript development. Ajv has the edge in overall health score (79/100), 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 ajv better than yup?
It depends on your needs. Ajv has a health score of 79/100 while Yup scores 67/100. Ajv has more weekly downloads (251.1M), suggesting broader adoption. Consider your specific requirements — bundle size, community support, and feature set — to decide which is the better fit.
Which has a smaller bundle size, ajv or yup?
Yup has the smaller gzipped bundle at 13.1 KB. A smaller bundle means faster load times for your users, which can positively impact SEO and user experience.
How many developers use ajv vs yup?
Based on npm download statistics, Ajv has approximately 251.1M weekly downloads and Yup has approximately 10.0M weekly downloads. These numbers reflect package installations, not unique developers, but they indicate relative adoption levels.
Which is better maintained, ajv or yup?
Ajv currently has the higher overall health score at 79/100. Ajv has a maintenance score of 80/100 and Yup scores 40/100 on maintenance.

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