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Security report for calendly.com

Calendly · Technology · United States

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

Security score

77/100

Risk levelLow

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

Calendly is a leading SaaS provider specializing in online appointment scheduling software, serving over 20 million professionals and a significant portion of Fortune 500 companies. The platform offers seamless calendar integrations, customizable event types, and automated meeting reminders, positioning itself as a market leader in scheduling solutions. The website reflects a mature, enterprise-grade service with a strong brand presence and comprehensive content tailored to professionals and businesses of all sizes. Technically, Calendly employs a modern web stack including React and Next.js, supported by Cloudflare DNS and various marketing and analytics tools such as Google Tag Manager, FullStory, and Marketo. The site is optimized for performance, mobile responsiveness, and accessibility, demonstrating a high level of digital maturity. From a security perspective, Calendly enforces HTTPS, implements key security headers, and maintains certifications like SOC 2 Type II and ISO 27001, indicating a robust security posture. However, DNSSEC is not enabled, and there is no public security.txt or explicit incident response contact, which are areas for improvement. Overall, Calendly presents a low-risk profile with strong business credibility, technical sophistication, and good privacy compliance. Strategic enhancements in DNS security and incident response transparency would further strengthen its security and trustworthiness.

Scanned

NIS2 and GDPR posture

GDPR outside view
70/ 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 calendly.com

This scan found 15 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

Email alerts on material changes and an exportable JSON history of every change.

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Full report

€39.90one-time

  • The complete analysis as a PDF you can cite
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Prices incl. 21% VAT. Secure checkout by Mollie; sold by SEQ SIA, Latvia.

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
87
DNS health
90
Network security
100
GDPR outside view
70
Average
77

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

Calendly operates in the technology sector with a SaaS business model focused on scheduling and productivity tools. Its competitive advantage lies in ease of use, extensive integrations, and enterprise adoption. Revenue streams likely include subscription fees from individual and enterprise customers. The target market spans individuals, small businesses, and large enterprises, with a notable presence in Fortune 500 companies. The company maintains a broad partnership ecosystem, integrating with major conferencing and calendar platforms. Growth indicators include a large user base and continuous feature expansion. The website content and branding reinforce a professional and trustworthy image, supporting strong market positioning.

Security posture

Calendly demonstrates a mature security posture with HTTPS enforcement, comprehensive security headers, and recognized certifications (SOC 2, ISO 27001). The absence of DNSSEC and a public security.txt file are minor gaps. No exposed sensitive data or vulnerable libraries were detected in the website content. Privacy policies and cookie consent mechanisms are in place, supporting GDPR compliance. Incident response contact details are not explicitly provided, which could hinder rapid communication during security events. Overall, the security culture appears strong but could benefit from enhanced transparency and DNS security measures.

Recommendations

  1. Enable DNSSEC to protect against DNS spoofing and improve domain security.
  2. Publish a security.txt file to facilitate responsible vulnerability disclosure.
  3. Provide explicit incident response contact information on the website.
  4. Regularly review and audit third-party scripts and tracking pixels for security risks.
  5. Enhance transparency around data retention policies and user privacy controls.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
Calendly
Description
Calendly is the modern scheduling platform that makes “finding time” a breeze. When connecting is easy, your teams can get more done.
Key services
Online appointment scheduling, Calendar integrations, Meeting reminders, Video conferencing integrations, Custom event types
Content quality
excellent
Branding
consistent

Technology

Stack
React, Next.js, Cloudflare DNS, Google Tag Manager, FullStory, ZoomInfo pixel, Maze analytics, Marketo, Clearbit
Frameworks
Next.js
Platforms
Web, Mobile apps (iOS, Android)
Performance
fast
Mobile
excellent
Accessibility
good
SEO
good

Security

Observed score
90/100
Good practices seen
  • HTTPS enforced
  • Security headers present
  • No exposed sensitive data in HTML
  • Use of reputable third-party security and analytics tools

Analytics and tracking

Services
FullStory, Google Analytics (via GTM), Maze
Tracking level
extensive
Privacy practices
good

Advertising

Tracking pixels
FullStory, ZoomInfo, Maze, Marketo, Clearbit
Marketing tools
Marketo, Clearbit
Transparency
good

Site quality

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

Key observations

  1. Website is fully accessible with no blocking or WAF challenges.
  2. Strong brand presence with consistent and professional design.
  3. Comprehensive privacy, cookie, and terms policies present.
  4. Use of multiple reputable third-party analytics and marketing tools.
  5. Good security posture with HTTPS and security headers.
  6. No exposed sensitive data or obvious vulnerabilities detected.
  7. WHOIS data supports legitimacy and domain age is appropriate.
  8. No direct company contact emails or phone numbers found on main page; contact primarily via forms.
  9. No security.txt or explicit incident response contacts found.
Technical notes

Notes

The website is built on a modern React and Next.js framework, leveraging Cloudflare DNS for domain resolution and multiple third-party marketing and analytics tools. The site is well-optimized for performance and mobile devices, with good SEO and accessibility practices. Hosting appears to be cloud-based with CDN support. The technical infrastructure supports scalability and reliability, suitable for an enterprise-grade SaaS platform. Opportunities exist to improve DNS security and streamline third-party script management to reduce potential attack surfaces.
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. 77/100Low24 findingsView report
  2. 77/100 +2Low25 findingsView report
  3. 75/100Medium22 findingsView report
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