Sustainable Substitutes for Google Calendar

An online calendar exposing users' personal scheduling data to Google's ecosystem.

Reasons to avoid Google Calendar

Avoid Google Calendar due to its opaque data handling, resulting in privacy concerns. Google has pushed its AI tool Gemini into Google Calendar, making it waste energy.

Google is known for its tax avoidance schemes and supports the Trump regime. Avoid all Google products, including Google Calendar and use a more sustainable alternative intead.

Ethical and Sustainable Google Calendar Alternatives

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  • Feasibility: How easily can the average user switch to this substitute? Higher feasibility results in a higher ranking.
  • Editor's Rating: How sustainable is the substitute? The more sustainability attributes it fulfils, the higher it is ranked.

Nextcloud Calendar

Nextcloud is a German self-hostable, open-source cloud storage and collaboration platform.

Nextcloud syncs files to your device. You can edit files offline and changes will sync automatically once you reconnect to the internet.
Some third party providers offer free plans with up to 5GB of storage. The self-hostable community edition is free and without licensing costs.
Nextcloud allows for real-time same-document collaboration.
Nextcloud is fully compatible with Microsoft Office and OpenDocument formats.
Nextcloud is ad free and does not monetise user-data.
Nextcloud does not track users or sell personal data, ensuring a private and secure experience with optional end-to-end encryption.
Nextcloud’s core software is fully open-source, allowing for independent audits and community-driven development.
Nextcloud is based in Germany, ensuring compliance with strong European privacy laws.
Nextcloud is designed to be self-hosted, giving users full control over their data and infrastructure.
Nextcloud became the first cloud software platform to earn the Blauer Engel ecolabel, emphasizing environmental responsibility.
Website

Tuta Calendar

A German email and calendar provider with encryption by default powered by green energy.

Tuta allows management of custom domain emails for paying users. The domain must be registered elsewhere though.
Tuta is ad-free, providing a clean and distraction-free email experience.
Tuta offers one email address with 1GB of storage free of charge and promises that this will not change.
Tuta is based in Germany, ensuring compliance with strong privacy laws and ISO/IEC 27001-certified data centers.
Tuta does not track users or display personalised ads, it offers end-to-end, quantum-safe encryption, ensuring a private email experience.
Tuta uses green energy to power its servers, reducing its environmental impact.
All Tuta clients are open-source, allowing for transparency and community contributions.
Website
calendar-online logo

Calendar.online

A lightweight online calendar from Germany with GDPR compliancy.

All servers are located in Germany, ensuring compliance with European data protection standards.
Calendar.online's focus is on a clean, functional interface without ad-distraction.
Calendar.online is GDPR compliant, stores IP addresses anonymously and does not pass or sell data to third parties.
Access is provided via unique links, and neither users nor administrators require an account or registration to use or share the calendar
A basic version is available free of charge, with the option to upgrade to paid plans for additional features.
No AI features "enrich" the product, keeping it lightweight and efficient.
Website

The 7 main issues with Google Calendar

Big Tech - Big Tech companies do not nourish people and planet. This is especially true in times of political tension.

Google Calendar is developed and owned by Google, one of the largest tech companies, contributing to market monopolisation and exploitative data practices. Source: EFF: Google Search Monopoly and Privacy Concerns (2025)

No Carbon Neutrality Goals - No goals for carbon neutrality is a bad sign as it shows lack of commitment to holding crucial thresholds for global climate warming.

Google recently erased its Carbon Neutrality Goals in favour of massively increasing its use of Gemini in its various products, including Google Calendar. Source: Toms Hardware: Google quietly removes net-zero carbon goal from website amid rapid power-hungry AI data center buildout (2025)

Lack of Transparency - Opacity in operations, data handling, or supply chains, making it difficult for users to understand practices.

Google lacks transparency in how user data from Google Calendar is used and shared. Source: FTC: Google’s Data Privacy Violations (2025)

Monopoly - Market dominance that stifles competition and limits user choice.

Using Google Password Manager increases vendor lock-in, making it harder to get away from Google products in general.

Tax Avoidance - Aggressive strategies are being deployed to avoid paying taxes.

Google is known for aggressively avoiding paying taxes, so much that taxing it got its own term: "Google tax". Source: Wikipedia: Google Tax

Support of Authoritarian Regimes - Companies actively supporting, financing and legitimising regimes and unethical policies.

Google has kissed Trump's ring by donating $1 million to his inauguration. Google has updated its products and policies to align with Trump’s political views.Time: How Google Appears to Be Adapting Its Products to the Trump Presidency (2025)

AI Bloat - Service has unnecessary or harmful AI features.

Gemini is integrated into Google Calendar, raising even more privacy concerns and increasing energy-consumption unnecessarily.Sources:Heise: Google integrates AI into Translate and expands learning tool (2025)ZDNET: Don't tell your AI anything personal, Google warns in new Gemini privacy notice (2024)Ars Technica: The hidden cost of Google’s AI defaults and the illusion of choice (2026)

Suggestions and Feedback

If you have suggestions for more alternatives or general feedback, please contact me via email or create an issue over on Codeberg. Suggest Substitute on Codeberg Write an Email