ajv
Extremely Popular
Version 8.18.0
85
ExcellentAnother JSON Schema Validator
- Weekly Downloads
- 241.0M
↑39%
- Bundle (gzip)
- 31.9 KB
- Updated
- Vulns
- 0
Health Score Breakdown
Maintenance
100
Popularity
100
Quality
50
Security
100
Stability
70
Ajv vs Joi
Side-by-side NPM package comparison
joi
Extremely Popular
Version 18.0.2
73
GoodObject schema validation
- Weekly Downloads
- 17.2M
↑31%
- Bundle (gzip)
- 52.6 KB
- Updated
- Vulns
- 0
Health Score Breakdown
Maintenance
60
Popularity
100
Quality
50
Security
100
Stability
70
Choosing between Ajv and Joi? 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 241.0M weekly downloads — roughly 14.0x more. Joi has 17.2M weekly downloads. Higher download counts generally indicate broader community adoption and a larger ecosystem of tutorials, plugins, and support.
Bundle Size
Ajv has the smallest gzipped bundle at 31.9 KB. Joi comes in at 52.6 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 85/100 (very good), with strong maintenance, security, popularity scores. Joi has an overall health score of 73/100 (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, actively maintained, strong security track record. Choose Joi if you value massive community and ecosystem, strong security track record.
Our Verdict
Both Ajv and Joi are solid choices for JavaScript development. Ajv has the edge in overall health score (85/100), 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 joi?
- It depends on your needs. Ajv has a health score of 85/100 while Joi scores 73/100. Ajv has more weekly downloads (241.0M), 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 joi?
- Ajv has the smaller gzipped bundle at 31.9 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 joi?
- Based on npm download statistics, Ajv has approximately 241.0M weekly downloads and Joi has approximately 17.2M weekly downloads. These numbers reflect package installations, not unique developers, but they indicate relative adoption levels.
- Which is better maintained, ajv or joi?
- Ajv currently has the higher overall health score at 85/100. Ajv has a maintenance score of 100/100 and Joi scores 60/100 on maintenance.