Google Calendar is convenient, but it means handing your entire schedule — meetings, travel, health appointments, everyone you invite — to an advertising company. If you’d rather own that data, the good news is that self-hosting a calendar in 2026 is easier than ever. This guide compares the leading open-source, self-hosted Google Calendar alternatives, what each is genuinely good at, and how to pick the right one.

First, decide what kind of calendar you actually need

Almost every wrong choice here comes from conflating three different things. Sort out which one you want and the decision gets easy:

• A CalDAV sync server. The direct Google Calendar replacement: it syncs two-way with the calendar apps already on your phone and laptop (iOS, Android via DAVx5, Thunderbird, Apple Calendar). You keep using your favorite app; only the server changes. Radicale, Baïkal, DAViCal.
• A full groupware suite. Calendar plus contacts, files, mail, tasks — a broader “de-Google everything” move. Nextcloud, SOGo.
• A web-based shared or event calendar. A calendar you and a group manage in the browser — an intranet team calendar, a club schedule, or a public events calendar embedded on a website. WebCalendar.

The key technical concept is CalDAV, the open standard for calendar sync. If “it has to sync to my iPhone’s built-in Calendar app” is a hard requirement, you want a CalDAV server (or a suite that includes one).

Quick comparison

Project	Type	Two-way CalDAV sync	Web UI	Stack	Footprint	Best for
Nextcloud	Full groupware	Yes (+ CardDAV)	Rich	PHP + MySQL/PostgreSQL	Heavy (512 MB–2 GB+)	Replacing all of Google
SOGo	Groupware	Yes (+ ActiveSync)	Yes	ObjC/GNUstep + DB	Medium–heavy	Teams needing Outlook/ActiveSync
Baïkal	CalDAV/CardDAV server	Yes	Admin panel only	PHP (sabre/dav) + SQLite/MySQL	Light (~40 MB)	Households & small teams that want sync
Radicale	CalDAV/CardDAV server	Yes	None (files)	Python, flat-file	Tiny (~20–30 MB)	Individuals & minimalists
DAViCal	CalDAV server	Yes	Minimal admin	PHP + PostgreSQL	Light–medium	Standards-strict CalDAV
WebCalendar	Web shared/event calendar	No (iCal import/export + feeds)	Full	PHP + MySQL/PostgreSQL/SQLite	Light	Group, intranet & public event calendars

The alternatives, in detail

Nextcloud — the full Google Workspace replacement

Nextcloud isn’t just a calendar; it’s an entire self-hosted cloud — files, calendar, contacts, mail, notes, tasks, and hundreds of add-on apps. Its Calendar app speaks CalDAV, so it syncs everywhere, and it has the most polished web interface of anything here. If your real goal is to leave Google entirely, Nextcloud is the answer.

Trade-off: it’s heavy. Expect PHP, a real database, and 512 MB–2 GB+ of RAM depending on users and installed apps. Running the whole suite just to get a calendar is overkill.

SOGo — groupware with ActiveSync

SOGo is groupware aimed at organizations: shared calendars, contacts, and webmail, with both CalDAV/CardDAV and Microsoft ActiveSync — handy if you have Outlook users. It’s a solid choice for a small company, though it’s a bigger operational commitment and some users report quirks with meeting invitations.

Baïkal — lightweight CalDAV with an admin panel

Baïkal is the sweet spot for most people who just want sync. Built on the well-respected sabre/dav libraries, it gives you a CalDAV/CardDAV server plus a simple web admin panel to create users and calendars — no config-file editing. It runs happily on SQLite for a household or MySQL for a small team, in around 40 MB of RAM.

Trade-off: the admin panel manages accounts, not events — you view and edit actual appointments in your phone/desktop client, not in Baïkal itself. Shared-calendar features are basic.

Radicale — the minimalist’s CalDAV server

Radicale is astonishingly small: a Python CalDAV/CardDAV server that stores everything as plain files on disk — no database, no PHP. That makes backups trivial (just copy or git commit the folder) and resource use nearly nothing. Perfect for one person or a household.

Trade-off: there’s no real web UI for managing calendars, and user management is via an htpasswd-style file. It’s a “set it and forget it” tool for people comfortable on the command line.

DAViCal — mature, standards-strict CalDAV

DAViCal is one of the oldest dedicated CalDAV servers (PHP + PostgreSQL) and is known for close adherence to the CalDAV standard, with good support for shared and delegated calendars. It’s less flashy and less actively developed than the others, but it’s proven. Consider it if strict standards compliance and fine-grained sharing matter more than a modern UI.

WebCalendar — the browser-based shared & event calendar

WebCalendar solves a different problem than the CalDAV servers above, and it’s worth being clear about the distinction. WebCalendar is a web-first, multi-user calendar: you and your users log in through the browser and manage events there, with user groups, access controls, and views designed for a shared or public schedule. It’s a natural fit for an intranet team calendar, a club or league schedule, or a public events calendar you want people to view (and optionally embed) on a website.

It supports iCalendar (.ics) import and export and can publish calendars as subscribable feeds, so people can subscribe to your public calendar in their own app. What it is not is a two-way CalDAV sync server — it isn’t designed to have your iPhone push edits back into it the way Radicale or Nextcloud are. If your need is “a shared calendar my group manages in a browser,” that’s exactly WebCalendar’s lane; if your need is “sync my personal calendar to every device,” reach for a CalDAV server.

WebCalendar is also lightweight and easy to run in Docker. If it fits your use case, you can be up in minutes: see How to Install WebCalendar with Docker Compose and then Run WebCalendar Behind a Reverse Proxy with HTTPS.

Which one should you pick?

• “Just replace Google Calendar on my phone.” → Baïkal (easiest) or Radicale (lightest).
• “Replace Google entirely — files, mail, the works.” → Nextcloud.
• “My company uses Outlook/ActiveSync.” → SOGo.
• “A shared team, club, or public event calendar people view in a browser.” → WebCalendar.
• “Strict CalDAV standards and delegated sharing.” → DAViCal.

Also worth knowing: EteSync offers end-to-end-encrypted calendars and contacts for the privacy-maximalist, and sabre/dav (which Baïkal is built on) can be embedded directly if you’re a developer building your own thing.

The bottom line

There’s no single “best” — it depends on whether you want device sync, a full cloud suite, or a shared web calendar. For most individuals wanting a private drop-in for Google Calendar, Baïkal or Radicale is the quickest win. For a group, club, or public events calendar you manage in the browser, WebCalendar is purpose-built for exactly that — and it’s a few minutes to try in Docker.

What did you end up self-hosting? Tell me in the comments — especially if I missed a project worth adding to this list.