# BeaverCheck Audit Report — https://yarnpkg.com

**Date:** April 22, 2026  
**URL:** https://yarnpkg.com  
**Overall Grade:** C (74/100)  
**Report:** https://beavercheck.com/results/642a5d7c-f78f-49f8-8af0-5693bc324361

## Top Findings

1. **[CRITICAL]** Content-Security-Policy header is missing — Security > Security Headers
2. **[CRITICAL]** HSTS header is missing — Security > Security Headers
3. **[CRITICAL]** No Content-Security-Policy header found — Security > Content Security Policy
4. **[CRITICAL]** 6 image(s) missing alt attribute — Accessibility > Alt Text Quality
5. **[WARNING]** Cross-Origin-Embedder-Policy header is missing — Security > Security Headers

---

## Lighthouse Scores

| Category | Score |
|----------|-------|
| Performance | 69 |
| Accessibility | 93 |
| Best Practices | 100 |
| SEO | 92 |

---

## Security

### Security Headers (F — 10/100)

*2 of 10 headers properly configured*

- **[CRITICAL]** HSTS header is missing — Strict-Transport-Security forces browsers to use HTTPS, preventing downgrade attacks. Add the header with a max-age of at least 1 year.
- **[WARNING]** X-Content-Type-Options header is missing — This header prevents MIME-type sniffing, which can lead to XSS attacks. Set it to 'nosniff'.
- **[WARNING]** X-Frame-Options header is missing — This header prevents clickjacking by controlling who can embed your page in a frame. Set it to DENY or SAMEORIGIN.
- **[WARNING]** Referrer-Policy header is missing — Controls how much referrer information is sent with requests. Set to 'strict-origin-when-cross-origin' or stricter.
- **[WARNING]** Permissions-Policy header is missing — Controls which browser features (camera, microphone, geolocation) are allowed. Set it to restrict unused features.
- **[CRITICAL]** Content-Security-Policy header is missing — CSP is the most important header for preventing XSS attacks. See the CSP section for detailed analysis.
- **[WARNING]** Cross-Origin-Opener-Policy header is missing — COOP isolates your browsing context, preventing cross-origin side-channel attacks. Set to 'same-origin'.
- **[WARNING]** Cross-Origin-Embedder-Policy header is missing — COEP prevents loading cross-origin resources without explicit permission. Required for SharedArrayBuffer and high-resolution timers.
- **[PASS]** X-Powered-By header is not present
- **[PASS]** Server header is present without version info

### Content Security Policy (F — 0/100)

*No enforcing CSP policy found*

- **[CRITICAL]** No Content-Security-Policy header found — CSP is the most effective defense against XSS attacks. Add a Content-Security-Policy header to restrict resource loading.

### TLS & Certificates (A+ — 100/100)

*TLS 1.2, 7 checks passed*

- **[PASS]** TLS 1.2 is used
- **[INFO]** TLS 1.3 is not negotiated — TLS 1.3 offers improved performance and security. Consider enabling it.
- **[PASS]** Strong cipher suite is used
- **[INFO]** HTTP/2 is not negotiated — HTTP/2 provides multiplexing and header compression for better performance.
- **[PASS]** Certificate is valid (expires in 62 days)
- **[PASS]** Certificate chain has 3 certificates
- **[PASS]** Certificate uses modern signature algorithm
- **[PASS]** Certificate covers 2 domain(s)
- **[PASS]** Certificate is issued by a trusted CA

### Cookie Security (A+ — 100/100)

*No cookies set — no cookie security risks*

- **[PASS]** No cookies set — no cookie security risks

---

## Advanced Security

### Subresource Integrity (F — 20/100)

*0 of 1 external resources have SRI*

- **[WARNING]** External script from www.datadoghq-browser-agent.com lacks integrity attribute — Without SRI, if this CDN is compromised, attackers could inject malicious code.

### JS Library Vulnerabilities (A+ — 100/100)

*No known vulnerabilities*

- **[PASS]** No known JavaScript library vulnerabilities detected

### Information Leakage (A+ — 100/100)

*No exposures*

- **[INFO]** No security.txt found — Consider adding a security.txt at /.well-known/security.txt.
- **[PASS]** No sensitive files exposed

### Email Security (F — 30/100)

*No DMARC*

- **[WARNING]** No DMARC record found — Without DMARC, email receivers have no policy for handling authentication failures.

### Permissions-Policy (D — 40/100)

*No header set*

- **[WARNING]** No Permissions-Policy header — Consider adding a Permissions-Policy header to restrict browser feature access from embedded content.

### CORS Configuration (B — 80/100)

*No CORS headers*

- **[PASS]** No CORS headers present — secure default

---

## Performance

### Page Weight Budget (C — 67/100)

*1.6 MB transferred, 32 requests*

- **[INFO]** Page weighs 4.1 MB (1.6 MB transferred)
- **[WARNING]** JavaScript is 596 KB — consider code splitting or lazy loading — Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
- **[PASS]** 32 HTTP requests
- **[INFO]** Estimated 0.34 g CO2 per page load

### Third-Party Impact (A+ — 100/100)

*3% third-party, 0 ms blocking*

- **[INFO]** Third-party code accounts for 3% of page weight (57.9 KiB of 1.6 MiB)
- **[PASS]** Third-party blocking time is low (0 ms)

### Text Compression (A+ — 100/100)

*All text resources are compressed*

- **[PASS]** All text resources are compressed

### Image Optimization (B — 75/100)

*12 images, 0 KB saveable*

- **[PASS]** All images are well-optimized

### JS Execution Cost (F — 20/100)

*4755ms total JS execution*

- **[WARNING]** https://yarnpkg.com/assets/js/1df93b7f.5320f051.js: 3414ms CPU time
- **[WARNING]** https://yarnpkg.com/assets/js/main.cb42a74a.js: 650ms CPU time
- **[INFO]** Unattributable: 238ms CPU time
- **[INFO]** https://yarnpkg.com/assets/js/2201.4e6213c6.js: 173ms CPU time
- **[INFO]** https://yarnpkg.com/: 163ms CPU time
- **[INFO]** Third-party scripts: 355ms (7% of total)

### Font Loading (A+ — 100/100)

*1 fonts (44 KB)*

- **[INFO]** 1 font(s) use font-display: swap (FOUT risk but functional)

### JS Bundles (D — 40/100)

*14 scripts, 286 KB unused*

- **[WARNING]** https://yarnpkg.com/assets/js/2201.4e6213c6.js: 136 KB unused (61%) — Consider code splitting or tree shaking to reduce unused code.
- **[WARNING]** https://yarnpkg.com/assets/js/2201.4e6213c6.js: unminified — 61 KB could be saved
- **[WARNING]** https://yarnpkg.com/assets/js/main.cb42a74a.js: 121 KB unused (39%) — Consider code splitting or tree shaking to reduce unused code.
- **[WARNING]** https://yarnpkg.com/assets/js/main.cb42a74a.js: unminified — 89 KB could be saved
- **[WARNING]** https://www.datadoghq-browser-agent.com/eu1/v4/dat...: 30 KB unused (60%) — Consider code splitting or tree shaking to reduce unused code.
- **[INFO]** Total unused JavaScript: 286 KB

### Resource Caching (A+ — 100/100)

*All resources properly cached*

- **[PASS]** No caching issues found

### Critical Rendering Path (A+ — 100/100)

*No render-blocking resources*

- **[PASS]** No render-blocking resources detected

### Resource Hints (A+ — 100/100)

*7 hints, 0 missing preconnects*

- **[PASS]** Page uses 7 resource hint(s)

### Page Weight Inventory (C — 55/100)

*32 resources · 1.6 MB · 286 KB savings available*

- **[WARNING]** Page weight 636 KB over 1MB target
- **[INFO]** ~286 KB of savings available
- **[INFO]** 7 third-party resources (3% of weight)
- **[INFO]** 4 resources over 200KB

### Render-Blocking Resources (A+ — 100/100)

*No render-blocking resources detected*

- **[PASS]** No render-blocking resources detected in <head>

### Third-Party Resources (A+ — 100/100)

*No third-party resources detected*


---

## Content Quality

### Links (A — 95/100)

*30 links checked, 29 healthy, 1 broken*

- **[WARNING]** 29 of 30 links are healthy
- **[WARNING]** Broken link: https://STXW7VT1S5-dsn.algolia.net — Found in <link href>. Returns HTTP 404.

### Mixed Content (A+ — 100/100)

*No mixed content detected — all resources use HTTPS.*

- **[PASS]** No mixed content detected — all resources use HTTPS

### Open Graph (A — 90/100)

*Open Graph tags are well configured for social sharing.*

- **[INFO]** og:title is short (16 characters) — Ideal length is 25–60 characters for social sharing previews.
- **[INFO]** og:description is short (43 characters) — Ideal length is 55–200 characters for social sharing previews.
- **[INFO]** Missing og:type — The og:type tag helps social platforms categorize the content.
- **[INFO]** Missing og:site_name — The og:site_name tag displays the website name in social previews.

### Structured Data (C — 40/100)

*No structured data (JSON-LD) found.*

- **[INFO]** No structured data (JSON-LD) found — Adding structured data helps search engines understand your content and can enable rich results.

---

## Infrastructure

### DNS Records (A+ — 100/100)

*2 A records, 31 ms lookup*

- **[PASS]** Resolves to 2 IPv4 address(es)
- **[PASS]** Has 2 IPv6 (AAAA) record(s)
- **[PASS]** 2 nameserver(s) configured
- **[PASS]** 3 mail exchanger(s) configured
- **[INFO]** CAA records not checked — CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
- **[PASS]** SPF record present in TXT
- **[PASS]** DNS resolution time: 31 ms

### Redirect Chain (A+ — 100/100)

*No redirects — direct access*

- **[PASS]** No redirects — direct access

### IPv6 Readiness (A+ — 100/100)

*IPv6 reachable (17 ms)*

- **[PASS]** IPv6 is configured and reachable at 2606:4700::6810:a878, 2606:4700::6810:a978

### Crawlability (A — 90/100)

*no robots.txt, sitemap with 400 URLs*

- **[INFO]** No robots.txt found — robots.txt is optional but recommended. It tells search engine crawlers which pages to index.
- **[PASS]** sitemap.xml is present
- **[PASS]** sitemap.xml is valid XML
- **[PASS]** sitemap.xml contains 400 entries

### URL Variants (A+ — 100/100)

*www/non-www, trailing slash, HTTP→HTTPS*

- **[PASS]** www/non-www redirect configured correctly (preferred: non-www)
- **[PASS]** HTTP correctly 301-redirects to HTTPS

### Domain Intelligence (A+ — 100/100)

*yarnpkg.com — via Cloudflare, Inc., 9 years, 8 months old*

- **[PASS]** Domain registered until Sep 22, 2027 (1 years, 5 months remaining)
- **[INFO]** DNSSEC is not enabled — DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.
- **[PASS]** Registrar: Cloudflare, Inc.
- **[WARNING]** Registrar lock is NOT enabled — The domain can be transferred without an unlock step. Enable registrar lock (clientTransferProhibited) in your registrar's control panel to protect against unauthorized or accidental transfers.

---

## Compliance

### WCAG Compliance (A+ — 100/100)

*No testable criteria*


### Cookie Consent & Privacy (B — 80/100)

*No consent signals detected*

- **[WARNING]** No privacy policy link detected — A privacy policy page is recommended for transparency and may be legally required.
- **[INFO]** No terms of service link detected
- **[INFO]** No cookie consent banner detected
- **[INFO]** This is an automated check, not legal advice — BeaverCheck detects technical indicators of consent management. This does not constitute a legal compliance assessment. Consult a privacy professional for GDPR/CCPA compliance.

### Language & i18n (A — 90/100)

*Lang attribute present*

- **[PASS]** <html lang> attribute is present
- **[PASS]** <html lang> value is valid
- **[INFO]** No Content-Language HTTP header
- **[INFO]** Language signals are inconsistent — The <html lang> attribute and Content-Language header should agree.

### Readability & Typography (A+ — 100/100)

*Font sizes and tap targets checked*


### Viewport Configuration (A+ — 100/100)

*Viewport properly configured*

- **[PASS]** Viewport meta tag is present
- **[PASS]** width=device-width is set
- **[PASS]** User zooming is allowed

### Third-Party Trackers (C — 55/100)

*1 trackers detected*

- **[INFO]** 1 third-party trackers detected — Found 1 analytics, 0 advertising, 0 marketing, 0 tag manager trackers.
- **[WARNING]** Trackers detected but no cookie policy found — This page loads 1 trackers but no cookie policy was detected. GDPR requires disclosure when using tracking cookies.
- **[WARNING]** Trackers detected but no privacy policy found — Most data protection regulations require a privacy policy when collecting user data via trackers.

### Cookie & Tracker Inventory (A+ — 100/100)

*0 cookies · 1 trackers · 0 pre-consent*

- **[INFO]** 1 third-party tracker(s) detected on page

---

## Legal

### Legal Page Ecosystem (F — 0/100)

*0 of 7 expected legal pages detected*

- **[WARNING]** Privacy Policy not detected — No link matching common Privacy Policy URL patterns or link text was found. Most websites are expected to have a Privacy Policy, especially those collecting user data.
- **[WARNING]** Terms of Service not detected — No link matching common Terms of Service URL patterns or link text was found. Most websites are expected to have a Terms of Service, especially those collecting user data.
- **[INFO]** Cookie Policy not detected — No link matching common Cookie Policy URL patterns or link text was found. Most websites are expected to have a Cookie Policy, especially those collecting user data.
- **[INFO]** Accessibility Statement not detected — No link matching common Accessibility Statement URL patterns or link text was found. Most websites are expected to have a Accessibility Statement, especially those collecting user data.
- **[INFO]** DMCA / Copyright Notice not detected — No link matching common DMCA / Copyright Notice URL patterns or link text was found. Most websites are expected to have a DMCA / Copyright Notice, especially those collecting user data.
- **[INFO]** Refund / Returns Policy not detected — No link matching common Refund / Returns Policy URL patterns or link text was found. Most websites are expected to have a Refund / Returns Policy, especially those collecting user data.
- **[INFO]** Acceptable Use Policy not detected — No link matching common Acceptable Use Policy URL patterns or link text was found. Most websites are expected to have a Acceptable Use Policy, especially those collecting user data.

### Copyright Notice (A+ — 100/100)

*© 2026 Yarn Contributors*

- **[PASS]** Copyright notice is up to date — Copyright notice is up to date: © 2026 Yarn Contributors
- **[PASS]** Copyright holder: Yarn Contributors

### Regulatory Indicators

*0 regulatory indicator(s) detected*

- **[INFO]** This is a technical scan, not a legal assessment — BeaverCheck detects technical indicators that may suggest regulatory relevance. This is not a compliance audit and should not be relied upon for legal decisions. Consult qualified legal counsel for compliance assessments.
- **[INFO]** No specific regulatory indicators detected — No strong signals for GDPR, CCPA, ADA, PCI, HIPAA, or COPPA were found. This does not mean these regulations don't apply — it means we didn't detect common technical indicators.

### Third-Party Data Sharing

*0 third-party service(s) detected*

- **[INFO]** Data inventory for transparency purposes — This inventory identifies third-party services that receive data from your site visitors. Under regulations like GDPR (Article 30), maintaining records of data processing activities is commonly considered a best practice. This automated scan provides a starting point — it may not capture all data flows.
- **[INFO]** No recognized third-party data-sharing services detected — This page does not appear to load external tracking, analytics, or advertising scripts.

### Compliance Badges (C — 55/100)

*0 compliance badge(s) detected*

- **[INFO]** No compliance badges detected — No recognized compliance certification badges or seals were found. This is common — many sites do not display compliance badges.

---

## Availability

### CDN & Delivery (A — 85/100)

*Cloudflare (DYNAMIC)*

- **[PASS]** Site is served via Cloudflare CDN (edge: CDG)
- **[INFO]** CDN cache status: DYNAMIC

### HTTP Caching (B — 70/100)

*public,max-age=0,must-revalidate*

- **[PASS]** Cache-Control header is set
- **[INFO]** No ETag or Last-Modified header — Conditional requests (304 Not Modified) are not possible without validators.

### Transport Security (B — 75/100)

*HTTP/3, HSTS, and TLS version analysis*

- **[INFO]** HTTP/3 (QUIC) not advertised — HTTP/3 eliminates head-of-line blocking. If your CDN supports it, consider enabling it.
- **[WARNING]** Missing Strict-Transport-Security header — HSTS tells browsers to only use HTTPS, preventing SSL stripping attacks.

---

## Accessibility

### Landmark Structure (A+ — 95/100)

*4 landmarks*

- **[PASS]** <main> landmark present
- **[PASS]** 1 <nav> landmark(s) found
- **[INFO]** No banner (header) landmark
- **[PASS]** Skip navigation link present

### Heading Hierarchy (A — 85/100)

*7 headings, 1 skip(s)*

- **[PASS]** Single H1 present
- **[WARNING]** Heading level skipped: H1 → H3 (missing H2) — Skipping heading levels breaks the document outline. Screen readers may interpret missing levels as structural errors.

### Alt Text Quality (C — 60/100)

*6 of 8 images have issues*

- **[CRITICAL]** 6 image(s) missing alt attribute — Images without alt text are invisible to screen readers.
- **[PASS]** 2 image(s) with good alt text

### Form Accessibility (A — 92/100)

*1 of 1 controls have issues*

- **[WARNING]** 1 control(s) rely on placeholder only — Placeholder text disappears on focus and is not a reliable label.

### Link & Button Quality (A — 88/100)

*16 links, 2 buttons — all OK*

- **[WARNING]** 4 link(s) open in new tab without warning — Add '(opens in new tab)' to link text or aria-label.
- **[PASS]** 12 link(s) with descriptive text

---

## UX

### 404 Error Page (B — 80/100)

*HTTP 404, custom page*

- **[PASS]** Correct 404 status code returned
- **[PASS]** Custom styled 404 page
- **[PASS]** Navigation links present on 404 page
- **[PASS]** Homepage link present on 404 page

### Favicon & Branding (F — 15/100)

*1 icon(s) detected*

- **[WARNING]** No favicon.ico at site root — Some older browsers, bookmark tools, and RSS readers look for /favicon.ico. Add one as a fallback.
- **[PASS]** HTML icon links detected
- **[INFO]** No apple-touch-icon detected — iOS devices use this when users add your site to their home screen. Add <link rel='apple-touch-icon' sizes='180x180' href='/apple-touch-icon.png'>.

### Web Manifest (D — 40/100)

*Not found*

- **[INFO]** No web manifest found — No manifest at standard paths (/manifest.json, /site.webmanifest). A manifest is optional but enables PWA features like home screen installation and standalone display.

### Dark Mode Support (D — 40/100)

*No dark mode signals*

- **[INFO]** No dark mode signals detected — Consider adding CSS with @media (prefers-color-scheme: dark) and <meta name='color-scheme' content='light dark'>.
- **[INFO]** Detection limited to meta tags and inline styles — External CSS files may contain prefers-color-scheme rules not visible to this scan.

### Print Stylesheet (D — 40/100)

*No print styles*

- **[INFO]** No print-specific styles detected — When users print this page, they get the screen layout including navigation and non-essential elements. Add @media print rules to hide navigation and optimize layout for paper.

### Navigation UX (F — 35/100)

*1 navigation pattern(s)*

- **[PASS]** Skip navigation link detected
- **[PASS]** 1 navigation landmark(s) detected
- **[PASS]** Hamburger menu detected (responsive design)

---

## SEO

### Canonical URL (A+ — 100/100)

*Properly configured*

- **[PASS]** Canonical tag present
- **[PASS]** Canonical is self-referencing
- **[PASS]** Canonical matches final URL after redirects
- **[PASS]** Canonical target returns 200

### Meta Tags (A — 85/100)

*Title: 16 chars*

- **[PASS]** Page title is set
- **[WARNING]** Title is only 16 characters — consider expanding
- **[INFO]** Title and H1 have very different wording — Alignment helps users confirm they've reached the right page.

### Content Depth (D — 40/100)

*209 words, Fairly Difficult*

- **[WARNING]** Page has 209 words — thin content — Most well-ranking pages have 300+ words of substantive content.
- **[INFO]** Reading level: Fairly Difficult (grade 7)
- **[WARNING]** Thin content — only 209 words

### Internal Links (A+ — 100/100)

*11 internal, 5 external*

- **[PASS]** 11 internal links (69%)
- **[PASS]** 100% of links use descriptive anchor text
- **[INFO]** 11 internal / 5 external links

### Image SEO (A+ — 95/100)

*8 images, 8 descriptive filenames*

- **[PASS]** All images have descriptive filenames
- **[INFO]** 6 image(s) missing alt text — see Accessibility tab

### Hreflang

*0 hreflang tags*


---

## Sustainability

### CO2 Per Page Load (A — 85/100)

*0.38g CO2 per view*

- **[PASS]** 0.38g CO2 per page view — This page transfers 1.6 MB, producing an estimated 0.38g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.08g, end-user device 0.29g.
- **[INFO]** At 10,000 monthly views: 46.0 kg CO2/year — With 10,000 page views per month, this page would generate approximately 46.0 kg of CO2 annually — equivalent to charging 5754 smartphones.
- **[PASS]** Green hosting reduces data center emissions

### Green Hosting (A+ — 100/100)

*Green (both)*

- **[PASS]** Both hosting and CDN use renewable energy
- **[INFO]** Cloudflare: Verified by the Green Web Foundation
- **[INFO]** Cloudflare: 100% renewable energy for global network since 2019
- **[INFO]** Green hosting status based on known provider commitments — Green hosting detection uses a curated database of provider renewable energy commitments. This is not a real-time verification. For authoritative checks, visit thegreenwebfoundation.org.

### Repeat Visit Weight (A+ — 100/100)

*100% cached*

- **[PASS]** 100% reduction on repeat visits — Returning visitors download only 6 KB (vs 1659 KB first visit). 31 of 32 resources are served from browser cache, saving 0.38g CO2 per repeat visit.
- **[INFO]** Repeat visit: 0.00g CO2 (first visit: 0.38g)

### Carbon Budget (A — 85/100)

*28th percentile*

- **[PASS]** 0.38g CO2 — below the sustainability target of 0.50g — Cleaner than an estimated 72% of websites analyzed. This page meets the Web Sustainability Guidelines target.
- **[INFO]** Estimated 28th percentile — Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.

### Transfer Efficiency (B — 80/100)

*83% efficient*

- **[INFO]** Transfer efficiency: 83% — An estimated 286 KB (17%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 286 KB of unused JavaScript. This wasted data produces 0.07g of unnecessary CO2 per page view.

---

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*Generated by [BeaverCheck](https://beavercheck.com) — https://beavercheck.com/results/642a5d7c-f78f-49f8-8af0-5693bc324361*