happy-dom
Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. It includes many web standards from WHATWG DOM and HTML.
20.3M weekly downloads · 246.0 KB gzip · Health 85/100
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Comparison guide
Happy-dom vs Jsdom
happy-dom is 2-4x faster than jsdom for Vitest. Compare DOM compatibility, performance benchmarks, and migration guide. Updated for 2026.
Quick Verdict
Smallest Bundle
Happy-dom
246.0 KB gzipped
Most Popular
Jsdom
110.7M weekly downloads
Best Maintained
Happy-dom
100/100 maintenance score
Highest Quality
Happy-dom
50/100 quality score
Overall Pick
Jsdom
Best all-around based on popularity, size, maintenance & quality
jsdom
A JavaScript implementation of many web standards
110.7M weekly downloads · 952.3 KB gzip · Health 85/100
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Choosing between Happy-dom and Jsdom? 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
Jsdom leads with 110.7M weekly downloads — roughly 5.4x more. Happy-dom has 20.3M weekly downloads. Higher download counts generally indicate broader community adoption and a larger ecosystem of tutorials, plugins, and support.
Bundle Size
Happy-dom has the smallest gzipped bundle at 246.0 KB. Jsdom comes in at 952.3 KB. A smaller bundle size means faster page loads, which improves user experience and Core Web Vitals scores.
Health Score Comparison
Happy-dom has an overall health score of 85/100 (very good), with strong maintenance, security, popularity scores. Jsdom 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 Happy-dom if you value massive community and ecosystem, actively maintained, strong security track record. Choose Jsdom if you value massive community and ecosystem, actively maintained, strong security track record.
Our Verdict
Both Happy-dom and Jsdom are solid choices for JavaScript development. Happy-dom 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 happy-dom better than jsdom?
- It depends on your needs. Happy-dom has a health score of 85/100 while Jsdom scores 85/100. Jsdom has more recorded weekly downloads (110.7M). Consider your specific requirements — bundle size, community support, and feature set — to decide which is the better fit.
- Which has a smaller bundle size, happy-dom or jsdom?
- Happy-dom has the smaller gzipped bundle at 246.0 KB. A smaller bundle means faster load times for your users, which can positively impact SEO and user experience.
- How many developers use happy-dom vs jsdom?
- Jsdom has more recorded weekly downloads (110.7M). Download counts reflect package installations, not unique developers.
- Which is better maintained, happy-dom or jsdom?
- Happy-dom has a maintenance score of 100/100. Happy-dom scores 100/100 and Jsdom scores 100/100 on maintenance.
The 2026 JavaScript Stack Cheatsheet
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