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Security report for codesandbox.io

CodeSandbox · Technology · Iceland

Medium risk. 4 critical or high findings in Security headers and SSL/TLS.

Security score

70/100

Risk levelMedium

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

CodeSandbox is a well-established cloud development platform founded in 2016, offering instant cloud development environments that enable developers to code, collaborate, and ship projects efficiently from any device. The platform targets developers and software engineers, positioning itself as a key player in the cloud-based development tools market. The website reflects a professional and consistent brand image with excellent design quality and user experience, optimized for mobile and accessibility. Technically, the site leverages modern web technologies including React and Next.js, hosted behind Cloudflare DNS services, ensuring fast performance and scalability. The infrastructure is modern and well-implemented, with good SEO and accessibility practices observed. However, explicit privacy and cookie policies are not detected in the provided content, which is a gap in compliance and user transparency. From a security perspective, HTTPS is enabled and domain registration includes clientTransferProhibited status, indicating domain transfer protection. However, DNSSEC is not enabled, and no security headers or vulnerability disclosure mechanisms are evident, suggesting room for improvement in security hardening and incident response readiness. No critical vulnerabilities or suspicious indicators were found. Overall, CodeSandbox presents a trustworthy and professional online presence with strong technical foundations but would benefit from enhanced privacy compliance and security policy disclosures to further strengthen user trust and regulatory adherence.

Scanned

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

NIS2 and GDPR posture

GDPR outside view
83/ 100 · Low
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 Strict-Transport-Security header

      Forces HTTPS connections

      What to do: Add "Strict-Transport-Security: max-age=31536000; includeSubDomains; preload"

      • CWE-319
      • OWASP A04:2025
      • ASVS V3.4.1
    • 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. 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 codesandbox.io

This scan found 22 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

€25per month

  • 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
15
Email security
65
DNS health
80
Network security
100
GDPR outside view
83
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

CodeSandbox operates in the technology sector, specifically targeting the developer tools market with cloud-based development environments. Its business model revolves around providing SaaS solutions that facilitate coding and collaboration in the cloud. The company benefits from a medium-sized market presence with a focus on innovation and developer productivity. The domain age and registration details align with the company's founding date, supporting legitimacy. The platform's partnership ecosystem is not explicitly detailed in the provided data, and no subsidiaries or parent companies are identified. The lack of visible contact information and privacy policies may impact customer trust and compliance perception. Strategically, CodeSandbox's competitive advantage lies in its instant cloud environment provisioning and cross-device accessibility, appealing to modern development workflows. Growth indicators include a professional website with strong branding and modern technology adoption. The company should consider enhancing transparency around privacy, security policies, and contact channels to improve customer confidence and regulatory compliance.

Security posture

The security posture of CodeSandbox is moderate to good based on the available data. The website enforces HTTPS, uses Cloudflare DNS, and has domain transfer protection enabled, which are positive indicators. However, the absence of DNSSEC reduces DNS security robustness. No security headers such as Content-Security-Policy, X-Frame-Options, or Strict-Transport-Security were detected in the provided content, which are recommended best practices to mitigate common web vulnerabilities. There is no evidence of a published security policy, incident response plan, or vulnerability disclosure program, which are important for mature security governance and responsible vulnerability management. No contact channels for security incidents (e.g., security@ or abuse@ emails) were found. No exposed sensitive data or vulnerable libraries were identified in the HTML content. Recommendations include enabling DNSSEC, publishing security and incident response policies, implementing security headers, and establishing a vulnerability disclosure mechanism to enhance security maturity and user trust.

Recommendations

  1. Enable DNSSEC on the domain to improve DNS security and prevent spoofing.
  2. Publish comprehensive privacy and cookie policies with clear GDPR compliance statements.
  3. Implement and publish security headers such as Content-Security-Policy, X-Frame-Options, and Strict-Transport-Security.
  4. Establish a vulnerability disclosure program or security.txt file to facilitate responsible reporting.
  5. Provide clear contact information including security incident response contacts to improve transparency and trust.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
CodeSandbox
Description
CodeSandbox is a cloud development platform that empowers developers to code, collaborate and ship projects of any size from any device in record time.
Key services
cloud development environments, collaborative coding, project shipping from any device
Content quality
excellent
Branding
consistent

Technology

Stack
React, Next.js, Cloudflare DNS, Web fonts (woff2), JavaScript ES6+
Frameworks
Next.js, React
Platforms
Cloud
Performance
fast
Mobile
excellent
Accessibility
good
SEO
good

Security

Observed score
75/100
Good practices seen
  • HTTPS enabled
  • clientTransferProhibited domain status

Analytics and tracking

Tracking level
minimal
Privacy practices
poor

Advertising

Transparency
poor

Site quality

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

Key observations

  1. Website is a professional cloud development platform
  2. No explicit privacy, cookie, or terms of service pages detected in provided content
  3. No contact emails or phone numbers explicitly found in the HTML content
  4. Strong branding and consistent design
  5. Modern technology stack with React and Next.js
  6. Good mobile and accessibility optimization
  7. No security.txt or vulnerability disclosure found
  8. No advertising or tracking scripts detected in provided content
Technical notes

Notes

The website is built using modern web technologies including React and Next.js, indicating a contemporary and scalable front-end architecture. Hosting is managed via Cloudflare DNS, which provides performance and security benefits. The site uses web fonts and asynchronous JavaScript loading to optimize performance. The design is responsive and accessible, with good SEO meta tags and Open Graph data for social sharing. No CMS was detected, suggesting a custom or framework-based site. Performance appears fast with efficient resource loading. However, technical improvements could include adding security headers and enabling DNSSEC. The absence of explicit privacy and cookie policies suggests a need for better compliance integration. Overall, the technical infrastructure is solid but can be enhanced with additional security and compliance features.
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. 70/100Medium31 findingsView report
  2. 70/100Medium31 findingsView report
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