Companies Using Cal.com

I run marketing at TechnologyChecker.io, and a booking embed is one of the first signals I look for, because it shows where a company expects its buyers to talk to it. Our October 2026 crawl finds Cal.com's embed on 6,536 live domains, 4,081 of them matched to a company. A domain counts when a page loads Cal.com's embed script from app.cal.com or app.cal.eu. Plain links to a cal.com page don't count, and nor do self-hosted copies, so this is the hosted, embedded base. I checked it before trusting it. On 15 random pages, 14 loaded the embed, and all 10 booking links I could read went to the site's own account or a named member of its staff.

How fast it's moving

The chart reads 3,857 domains in August, 6,406 in September and 6,536 in October. The August to September step is mostly ours. The set of domains we crawl turns over every month, with dead sites leaving and newly found ones arriving, and our detection widened that month as we captured more of each page. September to October is the cleaner read: a gain of 130 domains. Churn is real but modest. 835 domains dropped Cal.com on at least one hostname since 4 August, and 181 of them still run it on another, which leaves 654 that dropped it everywhere we look.

"Six in ten Cal.com companies were founded this decade. A list that young turns over with the startups on it, so I treat it as a monthly feed rather than a fixed account list." - Elif Arslan, CMO & Co-founder at TechnologyChecker.io

Sales signal: treat Cal.com as a steady pool of about 6,500 domains that still adds sites month to month, not a breakout story. The one dated event worth building a message around is April 2026, when Cal.com took its main codebase closed source. That reopened the self-hosting question for its most technical users.

Who the customers are

82.15% of matched companies with a known size have 1 to 10 employees and 14.9% have 11 to 50. Only 5 have more than 500. 61.32% were founded in the 2020s, against 43.89% on Calendly's profile. The named rows show what that looks like in practice. FOSSA routes demo requests through a team event, Keboola sends visitors to a team booking page, Evil Martians books exploration calls, and staff at RST Software and Rather Labs take intro calls on their own pages. Auxi'life, a French home-care company with 1,001 to 5,000 staff, is the largest employer among the 50 named rows. It's an outlier.

Sales signal: the buyer is usually a founder or the first sales hire. They picked a developer-friendly tool and will judge yours the same way, on API, embed quality and price per seat.

Europe, India and the agency belt

The United States leads with 945 matched companies, but the eight European countries in the top 15 add up to 1,067. India is second with 317, and Calendly's profile doesn't show India in its top five. Industry is narrower than geography. Software Development (16.48%), IT Services and IT Consulting (13.65%), Technology, Information and Internet (9.89%) and LinkedIn's older Information Technology & Services label (1.75%) make 41.77% together. Marketing, Design and Advertising Services add 19.59%.

Sales signal: this is a list for selling to software firms and agencies, not clinics or salons. Localise for Europe early. There are more European Cal.com companies than American ones, and France, Germany and the Netherlands all sit in the top seven.

Calendly next door

Our switching tests don't find a corridor between the two schedulers. 231 domains have carried both Cal.com and Calendly since we began tracking, and 98 still run both, 42.4% of them. For many sites the second scheduler is an addition, not a replacement, so we don't publish a switching table for Cal.com. The counts also aren't measured the same way. Our detection methods write-up explains why a plain link counts for Calendly but not for embed-only tools, and Calendly's 180,383 domains include those links.

"98 Cal.com domains still run Calendly as well. Two schedulers on one site usually means nobody has made the call yet, and that's the best moment for either vendor to get in touch." - Elif Arslan, CMO & Co-founder at TechnologyChecker.io

Sales signal: for Cal.com's own team, Calendly's domains filtered to software firms and agencies are the obvious prospect list. For Calendly, the 98 overlapping domains are a retention list worth a call this quarter.

The stack around it

Next.js runs on 32.14% of the 6,780 live Cal.com domains and Vercel hosts 31.28%. React Router is on 13.19% and Astro on 6.21%. WordPress is on only 16.18%, against 38.02% on Calendly's domains. Webflow (10%) and Framer (4.94%) are the no-code side. Analytics follows the same taste: Google Analytics is on 49.23%, Cloudflare's browser insights on 12.01%, and Umami (2.52%) and Plausible (2.27%) turn up too. Sanity, a headless CMS, is on 1.87%.

Sales signal: developer tools, headless CMSs and privacy-first analytics will find a better-qualified list here than in Calendly's WordPress-heavier base. Pitch on the stack they already chose.

What it costs

Cal.com's pricing page, checked on 14 October 2026, lists a Free plan for one user, Teams at $12 and Organizations at $28 per user a month billed yearly, and quoted Enterprise pricing. Teams adds round-robin scheduling, routing forms, team booking pages and removal of Cal.com branding. On 14 April 2026 the company moved its main codebase to closed source and published a community edition, Cal.diy, under the MIT licence.

Sales signal: the free single-user plan explains the size curve. Team pages (cal.com/team/...) and routing forms are listed as Teams features, so sites showing them, such as FOSSA, Keboola, Evil Martians and Bask Health, are on paid plans and have a budget line for scheduling.

Key takeaways

1. 6,536 live domains, 4th in Appointment Scheduling with 2.31%, counted on embeds only.

2. Very small and very young: 82.15% have 10 or fewer staff and 61.32% were founded in the 2020s.

3. More European companies (1,067 in the top 15) than American (945), with India second.

4. A developer stack: Next.js on 32.14%, Vercel on 31.28%, WordPress on only 16.18%.

5. Calendly runs beside it on 98 domains, and we see no switching corridor either way.

How to use this list

Filter by industry and country first, then dedupe by redirect target: 14.4% of a 388-domain sample forwarded to another domain, and one agency alone holds 63 lookalike domains. For the full list of 6,536 Cal.com domains with company size, country and stack, explore TechnologyChecker.io.