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IIS vs Windows Server

Based on 61 and 60 real audits

View IIS details | View Windows Server details
MetricIISWindows ServerWinner
Performance4445Windows Server
Accessibility8888Tie
Best Practices8485Windows Server
SEO9090Tie
Security6565Tie
TTFB534ms549msIIS
Composite7171Tie
Performance
IIS
44
Windows Server
45
Accessibility
IIS
88
Windows Server
88
Security
IIS
65
Windows Server
65
SEO
IIS
90
Windows Server
90
Composite
IIS
71
Windows Server
71

Windows Server outperforms IIS in 2 of 7 categories, with a stronger composite score (71 vs 71). IIS leads in TTFB.

When to choose IIS

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

When to choose Windows Server

Choose Windows Server when your primary concern is performance and best practices. Its audit data shows consistent strength in these areas across the sampled sites.

How this comparison was built

Scores are medians across 61 audited IIS sites and 60 audited Windows Server 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, IIS or Windows Server?
Based on real BeaverCheck audits, Windows Server sites score higher on Lighthouse performance (45 vs 44 on average).
Which has better security, IIS or Windows Server?
IIS sites score higher on security analysis (65 vs 65 on average).
Which has better accessibility, IIS or Windows Server?
Accessibility scores measured by Lighthouse WCAG 2.1 checks favor IIS (88 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, IIS or Windows Server?
IIS sites score higher on Lighthouse SEO signals (90 vs 90 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), IIS or Windows Server?
IIS sites show lower Time to First Byte (534 ms vs 549 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 IIS or Windows Server for my website?
Both platforms have trade-offs. Windows Server scores higher on overall composite score while IIS 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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