Is Cal.diy really free?

Yes. Cal.diy is open source: the code is public and installing it costs nothing. At most you pay for hosting if you put it on a server, often a few euros a month. Cal.com, on the other hand, costs €14 a month.

Do I need to code to install Cal.diy?

No. The level is advanced and the install takes about 45 minutes with the prompt from the page: Claude does the work, you answer its questions.

How is it different from Cal.com?

Cal.diy does most of what Cal.com does, without a subscription, and your data stays with you. The point by point comparison is on the page.

Yes. With an open source tool installed on your side, your files stay on your machine or your server. Nobody can close your account or change the price.

Free alternative

Free alternative to Cal.com

Cal.com costs €14 a month. Cal.diy does the same job for free, in open source: you install it on your machine or a small server, and you stop paying.

Public entry price, taken from Cal.com’s website (cal.com). Over a year, that is €168 that stays in your pocket.

What replaces Cal.com

The main alternative

Cal.diy

🔴 Advanced⏱️ ~45 min to installSave €12/mo

Cal.diy is your booking page: you send a link, the person picks a slot from your real availability, the meeting lands in your calendar and the video link is created automatically. It is the community edition of Cal.com: the same engine, all commercial code removed, and a fully open license. The difference with Calendly: no caps (event types, calendars, integrations, everything included), your link lives on YOUR domain, and your calendar data stays on your server. It is the only tool in this library I use in production for my own business, every day.

Loucash’s verdict on Cal.diy

9/10

This is the infrastructure my business runs on daily: every call with my students and clients goes through it, in production. I will not lie to you, it is the heaviest deployment in this library and genuinely an advanced level: you need a server, a database and some time ahead of you. But that is exactly where it pays off. You open one account per person on your team, each with their own link, calendar and availability, and you never pay per seat. Calendly at €12 per person per month, across five people over two years, is €1,440. Here, you pay for your server, full stop. The bigger your team grows, the wider the gap works in your favour. Two hard-earned traps to know. On Railway, outbound SMTP is blocked: I wired the emails through Resend's HTTP API, plan for it from day one. And on the Google Calendar side, any event marked Busy blocks your slots: switch your routine blocks to Free, or you will end up with two slots a day. One heads-up so you are not caught out: Cal.com's advanced team features (round robin distributed bookings, collective events) have been removed from this edition. Everyone gets their own account and link, which already covers the vast majority of needs.

Who it is for: You sell calls or follow-ups (consultations, audits, coaching), solo or with a team, and you want your booking link on your own domain without paying per seat.

See the full page →See the tool ↗

The prompt that installs Cal.diy

Paste this prompt into Claude: it checks the repository, asks you its questions and installs the tool step by step.

Déploie cal.diy (l'outil open source de prise de rendez-vous, repo calcom/cal.diy, image Docker officielle calcom/cal.diy) sur mon hébergement, avec une base PostgreSQL. Configure les variables d'environnement nécessaires (NEXTAUTH_SECRET, CALENDSO_ENCRYPTION_KEY, l'URL publique), branche l'envoi d'emails, puis vérifie que la page de réservation répond sur mon sous-domaine. Attention : si mon hébergeur bloque le SMTP sortant, passe par l'API HTTP d'un service d'emails comme Resend. Explique-moi chaque étape simplement, je débute.

Review the GitHub repository and check whether it is safe to install given my machine and my infrastructure. Ask me as many questions as possible, using widgets, to clarify my request and be as precise as you can.

Frequently asked questions

Is Cal.diy really free?: Yes. Cal.diy is open source: the code is public and installing it costs nothing. At most you pay for hosting if you put it on a server, often a few euros a month. Cal.com, on the other hand, costs €14 a month.
Do I need to code to install Cal.diy?: No. The level is advanced and the install takes about 45 minutes with the prompt from the page: Claude does the work, you answer its questions.
How is it different from Cal.com?: Cal.diy does most of what Cal.com does, without a subscription, and your data stays with you. The point by point comparison is on the page.
Do I own my data?: Yes. With an open source tool installed on your side, your files stay on your machine or your server. Nobody can close your account or change the price.