Quick Overview
- 1#1: Cronofy - Provides a real-time calendar synchronization API supporting Google, Microsoft, Apple, and other providers for seamless cross-platform syncing.
- 2#2: Nylas - Offers a unified API for syncing calendars, email, and contacts across major providers like Google, Outlook, and Exchange.
- 3#3: CalendarBridge - Enables two-way synchronization between Google, Office 365, and iCloud calendars without requiring app installations.
- 4#4: SyncGene - Synchronizes calendars, contacts, and tasks across Google, Outlook, Office 365, iCloud, and Exchange accounts.
- 5#5: CompanionLink - Delivers secure, direct USB, Wi-Fi, or cloud-based syncing of calendars, contacts, and tasks between desktops and mobile devices.
- 6#6: OneCal - Simplifies two-way syncing between Apple iCloud Calendar and Google Calendar for users of both ecosystems.
- 7#7: Sync2 - Synchronizes Outlook calendars, contacts, and tasks with Google, iPhone, Android, and other services.
- 8#8: gSyncit - Performs fast, two-way synchronization between Google Calendar and Outlook, Lotus Notes, or Palm Desktop.
- 9#9: Fantastical - Advanced calendar app with natural language input and seamless syncing across iCloud, Google, Exchange, and other services.
- 10#10: Zapier - Automates calendar event syncing and workflows between Google Calendar, Outlook, and hundreds of other apps via no-code integrations.
We evaluated tools based on functionality, performance reliability, ease of use, and overall value, ensuring they meet diverse needs—from individual cross-platform syncing to complex enterprise integrations.
Comparison Table
This comparison table explores popular calendar sync software tools, including Cronofy, Nylas, CalendarBridge, SyncGene, CompanionLink, and more, to highlight their unique strengths. Readers will learn about key features, integration options, and usability factors to find the best fit for their organizational needs.
| # | Tool | Category | Overall | Features | Ease of Use | Value |
|---|---|---|---|---|---|---|
| 1 | Cronofy Provides a real-time calendar synchronization API supporting Google, Microsoft, Apple, and other providers for seamless cross-platform syncing. | enterprise | 9.6/10 | 9.8/10 | 9.3/10 | 9.4/10 |
| 2 | Nylas Offers a unified API for syncing calendars, email, and contacts across major providers like Google, Outlook, and Exchange. | enterprise | 9.2/10 | 9.6/10 | 8.1/10 | 8.7/10 |
| 3 | CalendarBridge Enables two-way synchronization between Google, Office 365, and iCloud calendars without requiring app installations. | specialized | 8.7/10 | 8.5/10 | 9.2/10 | 8.6/10 |
| 4 | SyncGene Synchronizes calendars, contacts, and tasks across Google, Outlook, Office 365, iCloud, and Exchange accounts. | specialized | 8.1/10 | 8.7/10 | 8.2/10 | 7.6/10 |
| 5 | CompanionLink Delivers secure, direct USB, Wi-Fi, or cloud-based syncing of calendars, contacts, and tasks between desktops and mobile devices. | specialized | 8.4/10 | 9.1/10 | 7.8/10 | 8.2/10 |
| 6 | OneCal Simplifies two-way syncing between Apple iCloud Calendar and Google Calendar for users of both ecosystems. | specialized | 8.1/10 | 8.4/10 | 8.7/10 | 7.6/10 |
| 7 | Sync2 Synchronizes Outlook calendars, contacts, and tasks with Google, iPhone, Android, and other services. | specialized | 7.6/10 | 8.0/10 | 7.2/10 | 8.4/10 |
| 8 | gSyncit Performs fast, two-way synchronization between Google Calendar and Outlook, Lotus Notes, or Palm Desktop. | specialized | 7.6/10 | 8.4/10 | 6.9/10 | 8.2/10 |
| 9 | Fantastical Advanced calendar app with natural language input and seamless syncing across iCloud, Google, Exchange, and other services. | specialized | 8.7/10 | 9.2/10 | 9.5/10 | 8.0/10 |
| 10 | Zapier Automates calendar event syncing and workflows between Google Calendar, Outlook, and hundreds of other apps via no-code integrations. | other | 7.9/10 | 9.2/10 | 8.5/10 | 7.0/10 |
Provides a real-time calendar synchronization API supporting Google, Microsoft, Apple, and other providers for seamless cross-platform syncing.
Offers a unified API for syncing calendars, email, and contacts across major providers like Google, Outlook, and Exchange.
Enables two-way synchronization between Google, Office 365, and iCloud calendars without requiring app installations.
Synchronizes calendars, contacts, and tasks across Google, Outlook, Office 365, iCloud, and Exchange accounts.
Delivers secure, direct USB, Wi-Fi, or cloud-based syncing of calendars, contacts, and tasks between desktops and mobile devices.
Simplifies two-way syncing between Apple iCloud Calendar and Google Calendar for users of both ecosystems.
Synchronizes Outlook calendars, contacts, and tasks with Google, iPhone, Android, and other services.
Performs fast, two-way synchronization between Google Calendar and Outlook, Lotus Notes, or Palm Desktop.
Advanced calendar app with natural language input and seamless syncing across iCloud, Google, Exchange, and other services.
Automates calendar event syncing and workflows between Google Calendar, Outlook, and hundreds of other apps via no-code integrations.
Cronofy
enterpriseProvides a real-time calendar synchronization API supporting Google, Microsoft, Apple, and other providers for seamless cross-platform syncing.
OAuth-secured, credential-free access to read/write calendars across diverse providers with real-time syncing and elevated permissions.
Cronofy is a leading calendar synchronization platform that provides a secure API for integrating and syncing calendar data across over 50 providers, including Google Calendar, Microsoft Outlook/Exchange, Apple iCal, and more. It enables real-time bidirectional syncing of events, free/busy data, and availability without requiring users to share credentials, using OAuth-based authentication. Developers leverage it to build scheduling apps, booking systems, and CRM integrations with advanced features like conflict detection and automated rescheduling.
Pros
- Secure OAuth integration eliminates credential sharing risks
- Real-time bidirectional sync across 50+ calendar providers
- Advanced APIs for availability, booking pages, and conflict resolution
Cons
- Pricing scales with active users, costly at enterprise volumes
- Primarily API-focused, steeper learning curve for non-developers
- Limited built-in UI components; requires custom frontend work
Best For
Developers and SaaS teams building scalable scheduling, booking, or CRM applications needing robust multi-provider calendar sync.
Pricing
Free developer sandbox; paid plans from $0.80/active end-user/month (Growth), up to custom Enterprise pricing with volume discounts.
Nylas
enterpriseOffers a unified API for syncing calendars, email, and contacts across major providers like Google, Outlook, and Exchange.
Universal Sync Engine for bidirectional, real-time calendar normalization across disparate providers
Nylas is a developer-centric API platform specializing in seamless synchronization of calendars, emails, and contacts across major providers like Google Calendar, Microsoft 365, Outlook, and iCloud. It offers real-time bidirectional syncing, event normalization, and webhook notifications to keep calendars in sync effortlessly in custom applications. Designed for scalability, Nylas handles OAuth authentication, conflict resolution, and high-volume usage for enterprise-grade calendar integration.
Pros
- Broad support for 10+ calendar providers with unified data model
- Real-time sync via webhooks and delta streams for instant updates
- Robust scalability and reliability for high-volume enterprise use
Cons
- Requires coding knowledge; not a no-code solution
- Usage-based pricing can escalate with large user bases
- Initial setup involves API integration complexity
Best For
Developers and SaaS companies building apps that need reliable, multi-provider calendar synchronization at scale.
Pricing
Free Developer plan up to 10 active end-users; Pro tier at $0.39/active end-user/month (min $99/mo), with Enterprise custom pricing.
CalendarBridge
specializedEnables two-way synchronization between Google, Office 365, and iCloud calendars without requiring app installations.
Private event syncing that preserves confidentiality by displaying 'Busy' or custom placeholders instead of full details
CalendarBridge is a web-based calendar synchronization service that enables seamless two-way syncing between major platforms like Google Calendar, Microsoft 365, Apple iCloud, and more. It handles complex scenarios such as private event syncing (showing as 'Busy' or custom labels) and customizable filters to control what events sync. Users can set it up quickly without needing apps or sharing full calendar access, making it reliable for multi-account management.
Pros
- Seamless two-way sync across Google, Outlook, iCloud, and others
- Excellent private event handling without revealing details
- Simple web-based setup with powerful filtering rules
Cons
- Pricing scales per synced calendar pair, which can add up for multiples
- Lacks integration with tasks or contacts syncing
- No native mobile app for on-the-go management
Best For
Professionals and teams managing separate personal and work calendars across different providers who need reliable, privacy-focused syncing.
Pricing
Starts at $4.95/month per calendar pair (billed annually); free 14-day trial; higher tiers up to $9.95/month for advanced filtering and priority support.
SyncGene
specializedSynchronizes calendars, contacts, and tasks across Google, Outlook, Office 365, iCloud, and Exchange accounts.
Seamless two-way sync between otherwise incompatible services like iCloud Calendar and Google Calendar
SyncGene is a cloud-based service that provides two-way synchronization for calendars, contacts, and tasks across popular platforms like Google Calendar, Outlook, Office 365, iCloud, Yahoo, and more. It enables users to keep data consistent in real-time without installing desktop software, supporting automatic syncing at customizable intervals. The tool is particularly useful for multi-account users, with free and premium plans offering varying levels of sources and features.
Pros
- Broad compatibility with major calendar providers including Google, Outlook, and iCloud
- Automatic two-way sync with customizable intervals
- Web-based setup requiring no software downloads
Cons
- Free plan limited to 2 sources and basic features
- Requires granting third-party access which may raise privacy concerns
- Advanced scheduling and unlimited sources locked behind paid plans
Best For
Users juggling multiple calendar services like professionals with both personal iCloud and work Outlook accounts who need reliable cross-platform syncing.
Pricing
Free for 2 sources (1-way sync); Premium from $5.99/month (billed annually) for unlimited sources, 2-way sync, and advanced filters.
CompanionLink
specializedDelivers secure, direct USB, Wi-Fi, or cloud-based syncing of calendars, contacts, and tasks between desktops and mobile devices.
Direct USB sync for offline, secure calendar synchronization without internet dependency
CompanionLink is a veteran calendar synchronization tool that enables two-way syncing between desktop apps like Outlook, Google Calendar, and iCloud with Android, iOS, and other mobile devices. It offers flexible sync methods including USB, Wi-Fi, and cloud-based options, with advanced features like filtering, categories, and conflict resolution. Primarily a desktop application, it ensures reliable data consistency for users avoiding full cloud reliance.
Pros
- Broad platform compatibility including Outlook, Google, and iOS/Android
- Reliable two-way sync with USB/offline options for secure environments
- Advanced customization like filters, categories, and scheduling
Cons
- Dated user interface that feels clunky on modern systems
- Requires desktop installation; no standalone mobile app
- Initial setup can be complex for non-technical users
Best For
Desktop-heavy professionals using Outlook who need robust, customizable calendar sync to mobile devices without mandatory cloud services.
Pricing
One-time purchase from $49.95 (Express) to $99.95 (Pro); optional DejaCloud add-on at $19.95/year for wireless sync.
OneCal
specializedSimplifies two-way syncing between Apple iCloud Calendar and Google Calendar for users of both ecosystems.
Seamless two-way syncing between any supported calendar provider without native interoperability
OneCal is a web-based calendar synchronization service that enables two-way syncing between major providers like Google Calendar, Apple iCloud, Outlook/Office 365, and others. It automatically propagates events, updates, deletions, and recurring schedules across connected calendars while handling time zones and conflicts. Users can manage multiple calendars from a single dashboard without native app integrations.
Pros
- Broad compatibility with Google, Apple, Outlook, and more calendars
- Reliable two-way sync for events, recurrences, and time zones
- Simple web setup with real-time updates and conflict resolution
Cons
- Free plan limited to 2 calendars and 100 events/month
- No mobile apps, relying on web interface
- Subscription required for advanced features like unlimited syncs
Best For
Professionals and teams using mixed calendar ecosystems like Google Workspace and Apple Calendar who need hassle-free cross-syncing.
Pricing
Free tier (2 calendars, 100 events/mo); Pro $4.99/mo (unlimited); Team $9.99/mo per user.
Sync2
specializedSynchronizes Outlook calendars, contacts, and tasks with Google, iPhone, Android, and other services.
Direct, intermediary-free two-way sync between Outlook and Google/iCloud calendars
Sync2 by 4Team is a Windows-based synchronization tool designed for Microsoft Outlook users, enabling two-way syncing of calendars, contacts, and tasks with services like Google Calendar, iCloud, Android, and iPhone. It operates without requiring an Exchange server or Microsoft 365 subscription, supporting automatic background syncs and conflict resolution. The software ensures data consistency across devices, making it suitable for users reliant on desktop Outlook.
Pros
- Reliable two-way sync with Google Calendar, iCloud, and mobile devices
- One-time purchase model with no recurring fees
- Handles recurring events and conflict resolution effectively
Cons
- Limited to Windows and desktop Outlook (no Mac or web support)
- Setup requires initial configuration wizard and can be tricky for beginners
- Occasional delays or issues with very large calendars
Best For
Windows users with desktop Outlook who need to sync calendars and contacts to non-Microsoft services without a subscription.
Pricing
One-time fee of $29.95 for a single PC license; discounts for multiple licenses or bundles.
gSyncit
specializedPerforms fast, two-way synchronization between Google Calendar and Outlook, Lotus Notes, or Palm Desktop.
Broad support for syncing Outlook with lesser-known services like Toodledo and Evernote alongside major calendars
gSyncit is a Windows-only desktop application that provides two-way synchronization for calendars, contacts, tasks, and notes between Outlook and a wide array of cloud services including Google Calendar, iCloud, Toodledo, Evernote, and more. It bridges the gap between local desktop data and various online platforms, ensuring data consistency across ecosystems. Users can configure multiple sync profiles for flexible, automated syncing schedules.
Pros
- Extensive compatibility with Outlook and numerous cloud services like Google, iCloud, and Toodledo
- Reliable two-way sync with customizable profiles and scheduling
- Affordable one-time purchase model
Cons
- Limited to Windows platform only
- Dated user interface and somewhat complex initial setup
- Lacks mobile app or cross-platform support
Best For
Windows users heavily reliant on Outlook who need to sync calendars and tasks with multiple niche cloud services.
Pricing
One-time license fee of $19.95 for a single PC; free trial available.
Fantastical
specializedAdvanced calendar app with natural language input and seamless syncing across iCloud, Google, Exchange, and other services.
Natural language event creation and parsing
Fantastical is a premium calendar app from Flexibits that excels in syncing multiple calendar services like iCloud, Google Calendar, Exchange, Office 365, and CalDAV into a unified, customizable view. It features powerful natural language input for effortless event creation, such as typing 'Dinner with Sarah Friday 7pm' to schedule instantly. Available on macOS, iOS, iPadOS, and Windows, it supports advanced tools like calendar sets, templates, weather integration, and task management for enhanced productivity.
Pros
- Exceptional natural language processing for quick event creation
- Seamless multi-service calendar synchronization
- Highly customizable interface with calendar sets and widgets
Cons
- Subscription required for full premium features
- No web version or free tier beyond basic trial
- Occasional sync delays with non-Apple services
Best For
Apple ecosystem power users who value intuitive natural language input and advanced calendar management over basic free syncing tools.
Pricing
Free limited version; Pro subscription $6.99/month or $56.99/year per platform.
Zapier
otherAutomates calendar event syncing and workflows between Google Calendar, Outlook, and hundreds of other apps via no-code integrations.
Deep integrations with 6,000+ apps, allowing calendar events to trigger actions in virtually any connected service.
Zapier is a no-code automation platform that connects calendars like Google Calendar, Outlook, and Apple Calendar with over 6,000 other apps through customizable workflows called Zaps. It enables syncing events between calendars or triggering actions based on calendar changes, such as creating tasks or sending notifications. While versatile for complex automations, it relies on polling or webhooks rather than native real-time sync, making it more of a general integrator than a dedicated calendar sync tool.
Pros
- Vast library of 6,000+ app integrations for flexible calendar automations
- Multi-step Zaps for advanced syncing and conditional logic
- Pre-built templates to quickly set up common calendar workflows
Cons
- Sync delays due to polling intervals (up to 15 minutes on basic plans)
- Task-based pricing can become expensive for high-volume syncing
- Overkill and less efficient for simple calendar-to-calendar sync compared to specialized tools
Best For
Teams and power users who need to automate calendar events across multiple apps like CRM, email, and project tools.
Pricing
Free plan (100 tasks/month, 15-min updates); Starter from $19.99/month (750 tasks, 2-min updates); higher tiers up to $599/month for unlimited tasks.
Conclusion
The reviewed tools offer diverse solutions for seamless calendar syncing, with Cronofy emerging as the top choice, valued for its real-time cross-platform API supporting major providers. Nylas stands out with a unified API for calendars, email, and contacts, while CalendarBridge excels in two-way sync without app installations, making them strong alternatives for specific needs.
Ready to simplify your scheduling? Start with Cronofy to unlock reliable, cross-platform calendar synchronization—your time management will thank you.
Tools Reviewed
All tools were independently evaluated for this comparison
Referenced in the comparison table and product reviews above.