Cal.diy vs Open SaaS
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
Open-source, self-hosted scheduling app for booking meetings, a community fork of Cal.com.
Open source · MIT
Free, open-source starter kit for building a SaaS web app with React, Node.js and Prisma.
The short answer
Choose Cal.diy if you need…
- Individuals who want to self-host their own booking page
- Developers who want to study or modify a large TypeScript scheduling app
- People who want MIT-licensed code without enterprise add-ons
- Hobbyists comfortable setting up Node.js and PostgreSQL
Choose Open SaaS if you need…
- Developers who want a head start on a subscription-based web product
- Solo builders who want auth, payments and email already wired up
- Teams that plan to use an AI coding assistant and want project rules and plugins included
- Developers already comfortable with React and TypeScript
Side-by-side
| Cal.diy | Open SaaS | |
|---|---|---|
| Type | App | App |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 49.6k | 16.2k |
| Setup difficulty | Advanced | Intermediate |
| How you get it | Clone and build from source | Install with a package manager |
| Main language | TypeScript | MDX |
| Last code update | 4 days ago | 9 days ago |
What each one is
Cal.diy
Cal.diy is a scheduling platform you run on your own server, so people can book time with you through a calendar page. It is a fork of Cal.com with the commercial enterprise features removed and everything under the MIT license. The README says it is intended mainly for personal, non-production use by people comfortable with server administration.
Open SaaS
Open SaaS is a template for building a software-as-a-service web app. It comes pre-built with common pieces such as user login (email and social sign-in), payments via Stripe, Polar.sh or Lemon Squeezy, email sending, background jobs, a landing page and an admin dashboard. It is built on the Wasp full-stack framework, which uses React, Node.js and Prisma.
Best for
Cal.diy
- Individuals who want to self-host their own booking page
- Developers who want to study or modify a large TypeScript scheduling app
- People who want MIT-licensed code without enterprise add-ons
- Hobbyists comfortable setting up Node.js and PostgreSQL
Open SaaS
- Developers who want a head start on a subscription-based web product
- Solo builders who want auth, payments and email already wired up
- Teams that plan to use an AI coding assistant and want project rules and plugins included
- Developers already comfortable with React and TypeScript
Strengths
Cal.diy
- Fully MIT-licensed with no proprietary enterprise edition, according to the README
- No license key or Cal.com account required to run it
- Active community project with a large star count and recent pushes
Open SaaS
- Free and MIT-licensed, with many common SaaS features included out of the box
- Built on Wasp, which provides end-to-end type safety between backend and frontend
- Includes AI-assistant support (AGENTS.md, skills and a Claude Code plugin) for coding help
Not ideal for
Cal.diy
- Businesses needing production or enterprise scheduling, since the README points to Cal.com for that
- People without server administration experience, because the README warns self-hosting requires advanced knowledge
- Anyone wanting a hosted service, since the README says there is no managed version
Open SaaS
- Complete beginners to web development, since it assumes familiarity with React, Node and a command line
- Projects that need a different backend stack, because the template is built around Wasp, Prisma and React
- People looking for a finished product rather than a starting point to customize
Trade-offs
Cal.diy
- The README explicitly warns it is use-at-your-own-risk and mainly for non-production use
- Setup requires Node.js, PostgreSQL, environment secrets, and careful configuration
- Enterprise features such as Teams, SSO, and Workflows were removed
Open SaaS
- Depends on the Wasp framework, so you inherit its conventions and its release cycle
- The README is truncated here and does not detail every feature's setup effort, so the real integration work is unclear
- Requires familiarity with React, Prisma and deployment to get the most from it
Getting started
Cal.diy
Clone the repository
git clone https://github.com/calcom/cal.diy.gitGo to the project folder
cd cal.diyOpen SaaS
Install the Wasp CLI
npm i -g @wasp.sh/wasp-cliCreate a new SaaS app from the template
wasp new -t saasFrequently asked questions
What is the difference between Cal.diy and Open SaaS?
Cal.diy: Open-source, self-hosted scheduling app for booking meetings, a community fork of Cal.com. Open SaaS: Free, open-source starter kit for building a SaaS web app with React, Node.js and Prisma. Cal.diy suits individuals who want to self-host their own booking page, while Open SaaS suits developers who want a head start on a subscription-based web product.
Are Cal.diy and Open SaaS free?
Cal.diy: Free and open source. Open SaaS: Free and open source.
Which is easier to set up, Cal.diy or Open SaaS?
Open SaaS is easier to get started with (rated intermediate); Cal.diy is rated advanced and usually needs more setup.
Is Cal.diy or Open SaaS more popular?
Cal.diy has more GitHub stars (49.6k) than Open SaaS (16.2k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to Cal.diy and Open SaaS?
Other options people compare them with include Taxonomy, NotionNext, Wasp, AI Website Cloner, DocsGPT.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.