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core-js vs JSS

Based on 1582 and 14 real audits

View core-js details | View JSS details
Metriccore-jsJSSWinner
Performance3640JSS
Accessibility8890JSS
Best Practices8485JSS
SEO9189core-js
Security6568JSS
TTFB374ms306msJSS
Composite7274JSS
Performance
core-js
36
JSS
40
Accessibility
core-js
88
JSS
90
Security
core-js
65
JSS
68
SEO
core-js
91
JSS
89
Composite
core-js
72
JSS
74

JSS outperforms core-js in 6 of 7 categories, with a stronger composite score (74 vs 72). core-js leads in SEO.

When to choose core-js

Choose core-js when your primary concern is SEO. Its audit data shows consistent strength in these areas across the sampled sites.

When to choose JSS

Choose JSS when your primary concern is server response time and performance. Its audit data shows consistent strength in these areas across the sampled sites.

How this comparison was built

Scores are medians across 1582 audited core-js sites and 14 audited JSS sites in the BeaverCheck database. Every audit runs the same 100+ checks — Lighthouse performance, security headers, accessibility, SEO, server response time — against a real URL. No vendor input, no sponsorship, no affiliate links. Read the full methodology →

FAQ

Which is faster, core-js or JSS?
Based on real BeaverCheck audits, JSS sites score higher on Lighthouse performance (40 vs 36 on average).
Which has better security, core-js or JSS?
JSS sites score higher on security analysis (68 vs 65 on average).
Which has better accessibility, core-js or JSS?
Accessibility scores measured by Lighthouse WCAG 2.1 checks favor JSS (90 vs 88). Both technologies can be made fully accessible with care — the difference reflects common patterns in the sampled sites, not inherent platform limits.
Which is better for SEO, core-js or JSS?
core-js sites score higher on Lighthouse SEO signals (91 vs 89 on average), which cover meta tags, crawlability, mobile friendliness, and structured data. Content strategy and backlinks still matter more than platform choice for ranking.
Which has faster server response (TTFB), core-js or JSS?
JSS sites show lower Time to First Byte (306 ms vs 374 ms on average). TTFB depends heavily on hosting and CDN setup rather than the technology itself, but the sampled sites suggest a meaningful difference in common deployment patterns.
Should I choose core-js or JSS for my website?
Both platforms have trade-offs. JSS scores higher on overall composite score while core-js may excel in metrics you care about most. Run a free BeaverCheck audit on a real site using each to compare the metrics relevant to your use case.
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