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Security report for codepen.io

CodePen · Technology · United States

Low risk. 4 critical or high findings in Security headers, GDPR outside view and 1 other check.

Security score

76/100

Risk levelLow

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

CodePen is a well-established online platform founded in 2012 that serves as a social development environment for front-end developers and designers. It offers a comprehensive suite of services including an online code editor, project building, testing, asset hosting, and community engagement through challenges and sharing. The platform enjoys a strong market position as a leading tool in the front-end development community, trusted by major technology companies. Technically, CodePen employs modern web technologies such as React, SCSS, and JavaScript, with hosting and DNS services provided by reputable providers like Cloudflare and Firebase. The website is well-optimized for performance, mobile responsiveness, and accessibility, providing an excellent user experience. Security-wise, the site enforces HTTPS, uses sandboxed iframes for user-generated content, and maintains domain transfer protections, though it lacks DNSSEC and some security headers. Privacy policies are comprehensive and GDPR compliant, but the absence of a visible cookie consent mechanism is a minor gap. Overall, CodePen demonstrates a mature digital infrastructure and a strong security posture with room for incremental improvements.

Scanned

This is an earlier scan of codepen.io. View the latest report

NIS2 and GDPR posture

GDPR outside view
53/ 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

4 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 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 codepen.io

This scan found 16 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.

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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
65
Security headers
70
Email security
85
DNS health
80
Network security
100
GDPR outside view
53
Average
76

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

CodePen operates on a freemium business model with PRO accounts and Teams subscriptions, targeting front-end developers and designers globally. Its competitive advantage lies in its integrated online editor combined with a vibrant community and collaboration features. Revenue streams include paid PRO memberships and team plans. The platform's partnership ecosystem includes payment processors like Stripe and Braintree, and backend services via Firebase. The company maintains strong branding consistency and trust signals, including endorsements from major tech companies. Growth indicators include a large user base (1.8 million+ designers and developers) and active community engagement through challenges and social sharing. Strategic observations highlight CodePen's focus on innovation in front-end tooling and community building as key to sustaining market leadership.

Security posture

CodePen exhibits a solid security maturity level with HTTPS enforced site-wide, domain transfer protections, and sandboxed user content to mitigate risks. No exposed sensitive data or vulnerable libraries were detected in the analyzed content. However, the lack of DNSSEC and missing explicit security headers such as Content-Security-Policy and X-Frame-Options represent areas for enhancement. There is no publicly available security policy or incident response information, which could improve transparency and readiness. Privacy compliance is strong with a comprehensive privacy policy, but cookie consent mechanisms are absent, potentially impacting GDPR compliance. Overall, the security posture is robust but could benefit from formalized policies and additional technical controls.

Recommendations

  1. Enable DNSSEC on the domain to enhance DNS security and prevent spoofing.
  2. Implement and display a cookie consent banner to comply fully with GDPR and other privacy regulations.
  3. Add and enforce security headers such as Content-Security-Policy, X-Frame-Options, and Strict-Transport-Security.
  4. Publish a dedicated security policy and incident response plan accessible to users and security researchers.
  5. Provide clear and accessible contact channels for security incident reporting and vulnerability disclosures.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
CodePen
Description
CodePen is a social development environment for front-end designers and developers. Build and deploy websites, show off work, build test cases to learn and debug, and find inspiration.
Key services
Online code editor, Front-end code sharing, Project building and testing, Community challenges, Asset hosting, Collaboration features
Content quality
excellent
Branding
consistent

Technology

Stack
React, SCSS, JavaScript, Cloudflare DNS, Firebase, Stripe, Braintree
Frameworks
React
Platforms
Web
Performance
fast
Mobile
excellent
Accessibility
good
SEO
good

Security

Observed score
85/100
Good practices seen
  • HTTPS enforced
  • clientTransferProhibited domain status
  • No exposed sensitive data in HTML
  • Sandboxed iframes for user content

Analytics and tracking

Tracking level
moderate
Privacy practices
basic

Advertising

Ad networks
Carbon Ads, BuySellAds
Transparency
basic

Site quality

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

Key observations

  1. Website is a mature, well-established platform for front-end developers.
  2. Content is rich, professional, and community-focused.
  3. Strong branding and consistent design.
  4. No signs of malicious or suspicious activity.
  5. Security posture is good but can be improved with DNSSEC and security headers.
  6. Privacy policies are present and comprehensive but cookie consent mechanism is missing.
  7. No direct contact emails or phone numbers publicly listed.
  8. Advertising is present but limited to reputable ad networks.
Technical notes

Notes

The website is built on a modern technology stack including React for frontend rendering, SCSS for styling, and JavaScript for interactivity. Hosting and DNS are managed via Cloudflare and Firebase, ensuring fast and reliable delivery. The site demonstrates excellent mobile optimization and accessibility features, with well-structured HTML and SEO-friendly meta tags. Performance is optimized with asynchronous loading of scripts and use of CDN-hosted assets. Technical debt appears minimal, with opportunities for modernization including enhanced security headers and DNSSEC adoption. The platform's infrastructure supports scalability and collaboration features, positioning it well for continued growth and innovation.
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

Earlier scans of this domain

  1. 76/100Low24 findingsView report
  2. 76/100 −3Low24 findingsView report
  3. 79/100Low19 findingsView report
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