Comparison

Proton Calendar vs Notesnook

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Proton Calendar

This app helps you manage your schedule with privacy in mind. It offers various viewing options, reminders, and recurring event creation. All your data is protected by end-to-end encryption and strict Swiss privacy laws, ensuring your personal information is not tracked or harvested.

Highlights
  • Agenda and day view
  • View and reply to invites
  • Automatic event addition from email
  • Light and dark mode
  • Multiple reminders
  • Recurring events
  • Cross-device sync
Features
Read full description

A calendar is a record of your life: Proton Calendar helps keep it private. Make the most of your time - See your upcoming events as you like with agenda or day view - View and reply to invites - Events and invites are automatically added to your calendar from your Proton Mail inbox - View your schedule in light or dark mode - Add multiple reminders for your events - Create recurring events on a daily, weekly, monthly, yearly, or custom basis - Keep your calendar in sync across all your devices Private by default - No ads, no trackers, and no data harvesting - We can’t spy on your calendar or misuse your data - Protected by the same end-to-end encryption used in Proton Mail - Event names, descriptions, and participants are stored with zero-access encryption - Based in Switzerland, all your data is protected by strict Swiss privacy laws People before profits - Funded by users, not advertisers — Privacy is our business model - Built by scientists and engineers who met at CERN and MIT and founded Proton Mail - Used by high-profile journalists and organizations globally What others say about Proton: “Proton has now made it stupid-easy to encrypt your schedule. Information about what you plan to do, where, and with whom, can be just as sensitive as the messages you send and receive.” Gizmodo Follow Proton on social media for all the latest news and offers: Facebook: /proton Twitter/X: @protonprivacy Reddit: /protonmail Instagram: /protonprivacy EULA: http://www.apple.com/legal/itunes/appstore/dev/stdeula

About

Notesnook

This open-source app offers secure, encrypted note-taking and organization across all your devices. It features a robust editor, to-do lists, and a private journal with advanced security to protect your personal information.

Highlights
  • Military-grade encryption
  • Cross-platform synchronization
  • To-do lists and task management
  • Private journal with media support
  • Rich text and Markdown editor
  • Notebook organization
  • App lock with fingerprint support
Features
Read full description

Your notes are yours. Notesnook encrypts every one of them on your device before it ever reaches the cloud — so no one can read them. Not advertisers, not us. UNLIMITED NOTES. EVERY DEVICE. FREE. Most note apps cap the free plan until it hurts. Others stop after a few dozen notes. Notesnook never limits how much you write or how many devices you sync. A REAL EDITOR Headings, tables, code blocks, maths, outlines, Markdown and full-quality images. Notes that hold up whether you are writing a shopping list or a thesis chapter. ORGANISED AT ANY SIZE Nested notebooks, tags, colours, pinned and favourite notes, and search that stays instant at 10,000 notes. Link notes to each other and build your own private wiki. PRIVACY YOU CAN CHECK YOURSELF • End-to-end encryption is always on — you cannot switch it off, so you cannot forget • Encrypted on your device, in transit and at rest, using XChaCha20-Poly1305 and Argon2 • Even your notebook and tag names are encrypted • 100% open source under AGPLv3 — read every line, or run your own sync server • Recommended by Privacy Guides IMPORT YOUR OLD NOTES Bring your notes, notebooks and tags with you. Import from your previous notes app, plus plain Markdown and HTML files. EVERYWHERE YOU WRITE iPhone, iPad, Mac and the web. Sync is instant, and encrypted the whole way. ALSO INSIDE • Web clipper — save any article, ad-free and offline • Reminders across all your devices • Note version history, so nothing is ever really lost • Publish a note to a shareable link • Dark mode and custom themes FREE FOREVER Unlimited notes, unlimited devices, 50 notebooks, 50 tags and full end-to-end encryption. No ads. No trial countdown. PAID PLANS Add task lists, callouts, recurring reminders, more storage, and — on Pro — app lock, an encrypted vault and full-quality images. From $19.99 a year. Questions or feedback: support@streetwriters.co Privacy policy: https://notesnook.com/privacy Terms: https://notesnook.com/terms

Screenshots

Proton Calendar4 screens
Notesnook4 screens

Verdict

The call

The clearest difference is rating: Notesnook at 4.7 against Proton Calendar's 4.1. Notesnook also leads on review sentiment (79% vs 41%) and update cadence (every 8 days vs every 5 weeks). Proton Calendar's advantage is monetization model (free vs free with in-app purchases). On price, ratings volume, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Proton Calendar sells 2 one-off in-app purchases and Notesnook sells 17 in-app purchases, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Notesnook holds the better App Store score, 4.7 against 4.1. Both are backed by a comparable volume of ratings — 1.6K and 688 respectively. Written reviews point the same way: 41% of Proton Calendar's written reviews are positive against 79% of Notesnook's.

UpkeepUpdate frequency

Proton Calendar ships an update every 5 weeks, Notesnook every 8 days. Both last shipped on October 29, 2026.

Scorecard4 real differences · 6 level
Proton Calendar versus Notesnook: the parameters behind the verdict, then further details
ParameterProton CalendarNotesnook
PriceFreeFree
Rating4.1 (1.6K ratings)4.7 (688 ratings) — better
Positive reviews40.7% of reviews78.9% of reviews — better
Number of ratings1.6K — better688
Update frequencyEvery 5 weeksEvery 8 days — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS16.015.6 — better
Further details — not scored
Size185 MB82 MB
Age rating4+4+
DeveloperProton AGStreetwriters LLC

Customer experience

Proton Calendar

All ratings1,415 ratings
Positive71.1%
Neutral13.7%
Negative15.2%
Written reviews641 reviews
Positive40.7%
Neutral26.4%
Negative32.9%

Notesnook

All ratings681 ratings
Positive93.0%
Neutral2.3%
Negative4.7%
Written reviews402 reviews
Positive78.9%
Neutral6.5%
Negative14.7%

User reviews

Proton Calendar

From 1.6K App Store ratings

What we love

  • 🚀 Intuitive interface
  • 🔒 Secure and private
  • 👍 Good integration with Proton suite
  • 👍 Visually appealing design

Room to improve

  • 🐛 Slow performance and crashes
  • 🔍 Lacking search functionality
  • 📅 Missing advanced calendar views (week, month)
  • 🔗 Limited integration with other calendars

Notesnook

From 688 App Store ratings

What we love

  • 🚀 Fast and efficient
  • 🔒 Secure and private
  • 👍 Clean and intuitive UI
  • 👍 Cross-platform compatibility
  • 👍 Generous free tier

Room to improve

  • 🐛 Sync and login issues
  • 🐛 Buggy and crashes
  • 💰 Expensive premium tier
  • 🔒 Lack of free encryption features

Bugs and requests

Proton Calendar

Reported bugs

3 issues
  • Issues with time zone settings
  • Notifications not working reliably
  • Inability to edit shared events

Requested features

5 requests
  • Widgets for quick access
  • Ability to invite and share calendars with others
  • Support for importing/exporting calendar data
  • Customization options (colors, alerts, etc.)
  • iPad-optimized version

Notesnook

Reported bugs

3 issues
  • Crashes on launch on older iOS devices
  • Sync issues leading to data loss
  • Unreliable login and verification process

Requested features

5 requests
  • Improved search functionality
  • Reminders and calendar integration
  • Handwriting and drawing support
  • Multilingual support
  • Improved table and spreadsheet features

In-app purchases

2 purchases

Proton Calendar

One-time2
  • Mail Plus (1 year)$59.99
  • Proton Unlimited$149.99
17 purchases

Notesnook

Subscriptions17
  • Notesnook Pro$0.991 Month
  • Notesnook Essential Plan7 Days trial$1.991 Month
  • Notesnook Pro$2.491 Month
Show 14 more
  • Notesnook Pro Plan7 Days trial$2.991 Month
  • Notesnook Pro3 variants$4.491 Month
  • Notesnook Pro1 Month trial$4.491 Month
  • Notesnook Pro Plan7 Days trial$6.991 Month
  • Notesnook Believer Plan7 Days trial$8.991 Month
  • Notesnook Pro$9.991 Year
  • Notesnook Essential Plan14 Days trial$19.991 Year
  • Notesnook Pro$24.991 Year
  • Notesnook Pro Plan14 Days trial$29.901 Year
  • Notesnook Pro Yearly$49.991 Year
  • Notesnook Pro2 variants$49.991 Year
  • Notesnook Pro1 Year trial$49.991 Year
  • Notesnook Pro Plan14 Days trial$69.991 Year
  • Notesnook Believer Plan14 Days trial$89.991 Year

Questions

Is Proton Calendar free?
Proton Calendar is free to download, with in-app purchases available.
Is Notesnook free?
Notesnook is free to download, with in-app purchases available.
Which has better reviews, Proton Calendar or Notesnook?
Notesnook is rated higher. Proton Calendar averages 4.1 out of 5 from 1.6K ratings, while Notesnook averages 4.7 from 688 ratings.
Do Proton Calendar or Notesnook have ads?
Neither Proton Calendar nor Notesnook shows ads.
Which is updated more often, Proton Calendar or Notesnook?
Proton Calendar ships an update every 5 weeks, and Notesnook every 8 days. Most recently, Proton Calendar was updated on October 29, 2026 and Notesnook on October 29, 2026.

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