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Security report for jsdelivr.com

jsDelivr · Technology · N/a

Medium risk. 5 critical or high findings in Security headers, GDPR outside view and 1 other check.

Security score

70/100

Risk levelMedium

0–100, higher is better. How it is calculated

jsDelivr is a well-established free CDN service focused on delivering JavaScript and open source project files from npm and GitHub. Operating since 2012, it serves billions of requests monthly and is supported by major sponsors such as Cloudflare, Fastly, and IBM. The website demonstrates a strong market position as a reliable and fast CDN for developers and open source communities. Technically, jsDelivr employs a modern tech stack including Ractive.js, Bootstrap, jQuery, and Algolia for search, supported by a multi-CDN global infrastructure ensuring high performance and availability. Security posture is solid with HTTPS enforced and no exposed sensitive data, though explicit security headers and policies could be improved. Privacy compliance is generally good, but the absence of a cookie consent mechanism is a minor gap. WHOIS data is incomplete, which slightly impacts trust but is mitigated by the professional presentation and sponsorships. Overall, jsDelivr is a credible and technically mature service with room for enhanced security transparency.

Scanned

NIS2 and GDPR posture

GDPR outside view
58/ 100 · Medium
Checks completed
7of 7

NIS2 Art. 21(2)

  1. (a) Risk analysis and security policies: Not visible from outside
  2. (b) Incident handling: One indicator
  3. (c) Business continuity, backups and crisis management: Not visible from outside
  4. (d) Supply chain security: Not visible from outside
  5. (e) Secure acquisition, development and maintenance, including vulnerability handling: Partly checked
  6. (f) Assessing the effectiveness of security measures: Not visible from outside
  7. (g) Cyber hygiene and security training: Not visible from outside
  8. (h) Cryptography and encryption: Partly checked
  9. (i) HR security, access control and asset management: One indicator
  10. (j) Multi-factor authentication and secured communications: Not visible from outside

This scan rated NIS2 with an earlier keyword method that is no longer shown; rescan for the per-article view. Risk management, continuity, supply chain, training, MFA, management oversight (Art. 20) and incident reporting (Art. 23) need internal evidence, and Guard cannot tell whether NIS2 applies to this organisation.

GDPR is indicative only, based on publicly visible signals: Articles 7, 12, 13 and 32 of Regulation (EU) 2016/679 and Article 5(3) of the ePrivacy Directive. Not a certification or legal assessment.

Priority findings

5 findings rated critical or high. Fix these first.

  1. Security headers

    Security headers are instructions your web server sends to every visitor’s browser. Missing ones leave visitors more exposed to attacks such as clickjacking and injected scripts.

    • High

      Missing X-Frame-Options header

      Prevents clickjacking attacks

      What to do: Add "X-Frame-Options: DENY" or "X-Frame-Options: SAMEORIGIN"

    • High

      Missing Content-Security-Policy header

      Controls resources the browser is allowed to load

      What to do: Implement a Content-Security-Policy appropriate for your application

      • ASVS V3.4.3
      • OWASP Secure Headers: OWASP Secure Headers Project recommends Content-Security-Policy: default-src 'self'; form-action 'self'; base-uri 'self'; object-src 'none';…

  2. GDPR outside view

    These are the privacy signals visitors and data protection authorities look for under GDPR.

    • High

      No Cookie Policy found

      GDPR requires clear information about cookie usage

      What to do: Add a dedicated cookie policy explaining cookie usage and purposes

    • High

      No Cookie Consent Banner found

      GDPR requires explicit consent for non-essential cookies

      What to do: Implement a cookie consent banner that appears on first visit

  3. SSL/TLS

    TLS encrypts the connection and proves the site is really yours. Weak or expiring certificates trigger browser warnings and put traffic at risk.

    • High

      Weak SSL Key Length

      SSL certificate uses 256-bit key, which is considered weak

      What to do: Use at least 2048-bit RSA or 256-bit ECC key

      • CWE-326
      • OWASP A04:2025
      • Mozilla TLS: Mozilla Server Side TLS 6.0 intermediate: rsa_key_size 2048

Need hands-on remediation? Email guard@offseq.com

Keep watching jsdelivr.com

This scan found 20 issues across 6 checks. Monitoring re-runs those checks daily, emails you when something material changes and records each fix, so you can show progress.

Daily monitoring

Recommended

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  • TLS certificates and expiry
  • DNS records
  • SPF, DKIM and DMARC
  • Security headers
  • GDPR and NIS2 posture
  • Exposed services
  • Third-party trackers
  • Security score drift

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Results by check

Each check with its score, findings and the evidence it collected.

How this score is calculated

The security score runs 0–100, higher is better. It is the plain average of the security checks that completed in this scan, each counted equally. A check that could not run is left out: it counts neither as a pass nor as a fail.

Counted in this score

SSL/TLS
75
Security headers
40
Email security
70
DNS health
75
Network security
100
GDPR outside view
58
Average
70

Not counted

  • NIS2 outside view: Re-weights evidence from the TLS, email, DNS, network and hygiene checks, so counting it would count that evidence twice. Shown on its own.
  • OffSeq Observations: An AI reading of the site, useful context but not reproducible evidence. Shown on its own.

Findings that cap the score at 49

Each of these is serious on its own, so while any is present the site cannot rate better than high risk, however good the other checks are.

  • The certificate is not trusted by browsers
  • The website is not served over HTTPS
  • A database, remote desktop, file-sharing or Telnet service is reachable from the internet
  • The page loads a script from a compromised source
  • The domain registration has expired
  • SPF authorises every server to send mail as the domain

Partial scans

When the site blocks Guard or most checks cannot run, the score covers only the checks that ran (usually DNS and email), is capped at 75 and is shown as partial, without a risk level.

Risk levels

  • Critical0–25
  • High26–49
  • Medium50–75
  • Low76–100

Technical appendix

Business context, site observations and technical notes gathered during the scan, and the standards behind each reference.

Business context

Business profile

jsDelivr's business model centers on providing a free, high-performance CDN for open source projects, monetized indirectly through sponsorships from leading CDN and technology providers. Its target customers are developers and OSS maintainers requiring reliable package delivery. The platform's competitive advantage lies in its multi-CDN architecture, extensive global presence, and integration with npm and GitHub ecosystems. Growth is indicated by high request volumes and active community engagement via GitHub and social media. Partnerships with Cloudflare, Fastly, IBM, and others strengthen its infrastructure and market credibility. The company maintains a lean team and focuses on technical excellence and community support rather than direct revenue generation.

Security posture

jsDelivr exhibits a mature security posture with HTTPS enforced site-wide and no visible exposure of sensitive data. The use of reputable third-party libraries and multi-CDN providers enhances resilience. However, the site lacks explicit security headers such as Content Security Policy and HSTS, which are recommended best practices. There is no publicly available security policy or incident response contact information, which could hinder transparency and trust in case of security incidents. Privacy compliance is generally good, but the absence of a cookie consent banner is a compliance gap under GDPR. No vulnerabilities or malware indicators were detected in the content. Overall, jsDelivr is secure but could improve transparency and formal security documentation.

Recommendations

  1. Implement and publish a comprehensive security policy and incident response contact information to enhance transparency.
  2. Add explicit security headers including Content Security Policy (CSP), HTTP Strict Transport Security (HSTS), and X-Frame-Options.
  3. Deploy a visible cookie consent mechanism to comply fully with GDPR and other privacy regulations.
  4. Consider publishing a vulnerability disclosure policy or security.txt file to facilitate responsible reporting.
  5. Enhance WHOIS data transparency if possible to improve domain trustworthiness.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
jsDelivr
Description
jsDelivr is a free CDN optimized for JavaScript and ESM delivery from npm and GitHub, serving more than 150 billion requests per month. It supports all web formats and has been operating since 2012.
Key services
CDN delivery of npm and GitHub hosted files, Real-time search of npm packages, API for package metadata and download statistics, Custom CDN endpoints for OSS projects
Content quality
excellent
Branding
consistent

Technology

Stack
Ractive.js, Bootstrap 3.3.7, jQuery 3.6.3, Algolia search, Font Awesome 4.7.0, Google Fonts, CDN delivery via jsDelivr network
Frameworks
Ractive.js
Platforms
Web
Performance
fast
Mobile
excellent
Accessibility
good
SEO
good

Security

Observed score
85/100
Good practices seen
  • HTTPS enforced (implied by https URLs)
  • No exposed sensitive data in HTML
  • Use of reputable third-party libraries

Analytics and tracking

Services
Algolia
Tracking level
minimal
Privacy practices
good

Advertising

Tracking pixels
Algolia
Marketing tools
Newsletter subscription via Mailchimp
Transparency
basic

Site quality

Design
excellent
User experience
excellent
Content relevance
excellent
Navigation
excellent
Professionalism
excellent
Trustworthiness
high

Key observations

  1. Website is fully accessible with rich content and no blocking detected.
  2. Professional and consistent branding with clear business focus on free CDN for open source projects.
  3. Strong technical infrastructure with multi-CDN global network and modern web technologies.
  4. No explicit cookie consent mechanism found despite GDPR compliance indications.
  5. Contact information is limited to a single email and newsletter form; no phone or physical address found.
  6. No explicit security policy or incident response information published.
  7. WHOIS data is incomplete or unavailable, which slightly impacts trust but not critical given other trust signals.
Technical notes

Notes

The website uses a modern and efficient technology stack including Ractive.js for UI, Bootstrap for styling, jQuery for DOM manipulation, and Algolia for search functionality. It leverages multiple CDN providers for global content delivery, ensuring fast performance and high availability. The site is mobile-optimized with responsive design and good accessibility features. SEO is well addressed with proper meta tags and structured data in JSON-LD format. The infrastructure is robust, but there is an opportunity to improve security headers and privacy mechanisms. Overall, the technical implementation supports the business goals effectively with minimal technical debt.
Standards and sources

Reference chips under each finding point to the standard, regulation or specification the finding relates to. They are taken from the official datasets below and mapped conservatively: a finding with no defensible link shows none. NIS2 and GDPR references mark where a finding is relevant evidence, not a compliance verdict. Implementing Regulation (EU) 2024/2690 binds digital infrastructure and digital service providers; for other entities it is the most detailed public reading of the Article 21 measures. WCAG, EN 301 549, European Accessibility Act and Web Accessibility Directive references name the requirement an automated accessibility rule relates to; they are not a conformance verdict.

Retrieved 2026-10-25

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