# What does Calendar use? Calendar (calendar.com) shows public evidence of 25 tools, according to runsonwhat (last checked 2026-10-20). - Industry: Internet - Size: 11–50 employees - Based in: Spokane, United States - Founded: 2018 - LinkedIn: https://www.linkedin.com/company/calendar ## Edge & Hosting | Tool | Category | Evidence | Since | |---|---|---|---| | [Cloudflare](https://www.runsonwhat.com/reverse/cloudflare) | CDN & Edge | DNS records, Website code | | | [Amazon Web Services](https://www.runsonwhat.com/reverse/aws) | Hosting & Cloud | Website code | | | [Amazon CloudFront](https://www.runsonwhat.com/reverse/cloudfront) | CDN & Edge | Website code | | ## Application | Tool | Category | Evidence | Since | |---|---|---|---| | [Google Fonts](https://www.runsonwhat.com/reverse/google-fonts) | Media & UI | Website code | | | [Font Awesome](https://www.runsonwhat.com/reverse/fontawesome) | Media & UI | Website code | | | [React](https://www.runsonwhat.com/reverse/react) | Frontend | Website code | | | [Tailwind CSS](https://www.runsonwhat.com/reverse/tailwind) | Frontend | Website code | | | [Stripe](https://www.runsonwhat.com/reverse/stripe) | Payments & Billing | DNS verification records, Website code | | | [Gatsby](https://www.runsonwhat.com/reverse/gatsby) | Frontend | Website code | | ## Data & Observability | Tool | Category | Evidence | Since | |---|---|---|---| | [Google Analytics](https://www.runsonwhat.com/reverse/ga) | Analytics | Website code | | | [Google Tag Manager](https://www.runsonwhat.com/reverse/gtm) | Analytics | Website code | | | [Amplitude](https://www.runsonwhat.com/reverse/amplitude) | Analytics | Website code | | ## Go-to-market | Tool | Category | Evidence | Since | |---|---|---|---| | [WordPress](https://www.runsonwhat.com/reverse/wordpress) | Website & CMS | Website code | | | [Google Ads](https://www.runsonwhat.com/reverse/google-ads) | Ads & Pixels | Website code | | | [Meta Pixel](https://www.runsonwhat.com/reverse/meta-pixel) | Ads & Pixels | Website code | | | [Brevo](https://www.runsonwhat.com/reverse/brevo) | Marketing | DNS verification records, Email records, Website code | | | [Zendesk](https://www.runsonwhat.com/reverse/zendesk) | Support & Docs | Custom domain | | | [Ahrefs](https://www.runsonwhat.com/reverse/ahrefs) | Marketing | DNS verification records | | | [PartnerStack](https://www.runsonwhat.com/reverse/partnerstack) | Marketing | Website code | | ## Company Ops | Tool | Category | Evidence | Since | |---|---|---|---| | [Microsoft 365](https://www.runsonwhat.com/reverse/microsoft-365) | Workspace | DNS verification records | | | [Google Workspace](https://www.runsonwhat.com/reverse/google-workspace) | Workspace | Email records, Website code | | | [reCAPTCHA](https://www.runsonwhat.com/reverse/recaptcha) | Security & Compliance | Website code | | | [SendGrid](https://www.runsonwhat.com/reverse/sendgrid) | Email Delivery | Email records, Website code | | ## FAQ ### What tools does Calendar use? As of October 2026, runsonwhat has found 25 tools at Calendar (calendar.com) in public records. Edge & Hosting: Cloudflare, Amazon Web Services and Amazon CloudFront. Application: Google Fonts, Font Awesome and React. Data & Observability: Google Analytics, Google Tag Manager and Amplitude. Go-to-market: WordPress, Google Ads and Meta Pixel. Company Ops: Microsoft 365, Google Workspace and reCAPTCHA. Last checked October 20, 2026. ### What cloud does Calendar run on? Calendar uses Amazon Web Services for hosting and cloud infrastructure, according to runsonwhat (October 2026). runsonwhat found Amazon Web Services through Amazon Web Services code on calendar.com. Amazon Web Services is used by 145,627 companies runsonwhat tracks. ### What email provider does Calendar use? Calendar uses Microsoft 365 for email and office software, alongside Google Workspace, according to runsonwhat (October 2026). runsonwhat found Microsoft 365 through a DNS verification record for Microsoft 365. Microsoft 365 is used by 710,128 companies runsonwhat tracks. ### What does Calendar use for customer support? Calendar uses Zendesk for customer support and documentation, according to runsonwhat (October 2026). runsonwhat found Zendesk through a subdomain that points at Zendesk. Zendesk is used by 41,795 companies runsonwhat tracks. ### What payment provider does Calendar use? Calendar uses Stripe for payments and billing, according to runsonwhat (October 2026). runsonwhat found Stripe through a DNS verification record for Stripe and code on calendar.com. Stripe is used by 28,060 companies runsonwhat tracks. ### What analytics tools does Calendar use? Calendar uses Google Analytics for analytics, alongside Google Tag Manager and Amplitude, according to runsonwhat (October 2026). runsonwhat found Google Analytics through Google Analytics code on calendar.com. Google Analytics is used by 878,878 companies runsonwhat tracks. ### Does Calendar use Google Fonts? Yes. runsonwhat found Google Fonts at Calendar through Google Fonts code on calendar.com. Google Fonts is a Media & UI tool used by 809,049 companies runsonwhat tracks. ### Which companies have a tech stack similar to Calendar's? The companies with the stacks most like Calendar's are Staytuned, Techies.com, GapMaps and Crazy Egg, according to runsonwhat (October 2026). Each shares 7 to 15 tools with Calendar, and rare tools count for more than common ones like Google Workspace, so the match reflects real stack choices. ### How does runsonwhat know what Calendar uses? runsonwhat reads public records only. Of the 25 tools at Calendar, 16 were found through code on calendar.com, 6 through DNS records, 2 through email records and 1 through subdomains that point at the vendor. A tool is listed only when a direct record backs it up; DNS is rechecked weekly and calendar.com about monthly. --- Source: runsonwhat, https://www.runsonwhat.com/company/calendar.com (updated October 2026). Counts are companies with direct public evidence of the tool (DNS records, certificates, website code, a real-browser crawl, subprocessor lists), so they are lower bounds. Methodology: https://www.runsonwhat.com/methodology.