Outlook Google Calendar Sync
What Outlook Google Calendar Sync is
Outlook Google Calendar Sync, or OGCS, is a free open-source Windows application for synchronizing Outlook and Google calendars in two directions. It can transfer subjects, descriptions, locations, attendees, reminders, availability, privacy settings and categories or colours. Users choose date ranges and automatic sync frequency, merge new events into destination calendars and request confirmation before deletions. Version 3 connects directly to Outlook Online, while version 2 requires classic Outlook and is in corrective maintenance mode. OGCS is available as an installed or portable application, including from a USB drive. The stated minimum requirement is Windows with .NET Framework 4.5; administrator privileges and a direct internet connection are not required. OAuth2 handles Google and optional Microsoft cloud authentication, and access can be revoked. The maker says calendar data is not accessed or stored without consent. Telemetry can be disabled, while daily logs remain up to 30 days. Formal support is not provided; community help and bug reporting are offered.
Who it suits
It suits Windows users who need customizable two-way synchronization between Outlook and Google calendars. Portable use and configurable deletion prompts may help people managing calendars across computers.
What it does well
- Two-way Outlook and Google calendar synchronization
- Supports detailed event attributes
- Installed and portable Windows versions
- OAuth2 access can be revoked
- Telemetry can be disabled
What to know first
- Windows-only application
- Version 2 requires classic Outlook
- No formal support
- Requires .NET Framework 4.5
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Free | Free · £10 or more donation hides splash screen | Free |
As outlookgooglecalendarsync.com lists them, read 12 Oct 2026. The maker's own page has the final word.
Verdict
OGCS provides configurable, bidirectional calendar synchronization at no charge, with installed and portable Windows options. Users should note the Outlook version differences and reliance on community support.
Facts from Outlook Google Calendar Sync's own pages
- Authentication
- The application authenticates to Google and optionally Microsoft cloud accounts using OAuth2, and the site says users can revoke access at any time. · outlookgooglecalendarsync.com, 12 Oct 2026
- Calendar data
- The privacy policy says calendar data is not accessed, viewed, or stored without user consent and is never commoditized. · outlookgooglecalendarsync.com, 12 Oct 2026
- Calendar sync
- two_way · outlookgooglecalendarsync.com, 22 Sept 2026
- Deployment
- OGCS is available as an installed or portable Windows application, and the portable version can run from a USB drive. · outlookgooglecalendarsync.com, 12 Oct 2026
- Event details
- Supported event attributes include subject, description, location, attendees, reminders, availability, privacy, and categories or colours. · outlookgooglecalendarsync.com, 12 Oct 2026
- Free plan
- Yes · outlookgooglecalendarsync.com, 22 Sept 2026
- Open source
- The maker describes OGCS as open source and free, with no functionality restrictions as a project mission. · outlookgooglecalendarsync.com, 12 Oct 2026
- Outlook support
- Version 3 can connect directly to Outlook Online; version 2 requires the classic Outlook application and is in corrective maintenance mode. · outlookgooglecalendarsync.com, 12 Oct 2026
- Purpose
- OGCS synchronizes Outlook and Google calendars, including two-way synchronization. · outlookgooglecalendarsync.com, 12 Oct 2026
- Requirements
- The site lists Windows with .NET Framework 4.5 as the minimum requirement and says administrator privileges and a direct internet connection are not required. · outlookgooglecalendarsync.com, 12 Oct 2026
- Shared calendars
- Yes · outlookgooglecalendarsync.com, 22 Sept 2026
- Support
- The maker says the open-source software has no formal support and directs users to community help and bug reporting. · outlookgooglecalendarsync.com, 12 Oct 2026
- Sync controls
- Users can customize the date range and automatic sync frequency, merge new events into destination calendars, and choose to be prompted before item deletions. · outlookgooglecalendarsync.com, 12 Oct 2026
- Telemetry and logs
- The application offers an option to disable all telemetry, and its daily log files are kept for up to 30 days unless deleted sooner. · outlookgooglecalendarsync.com, 12 Oct 2026
Where Outlook Google Calendar Sync stands on Freedom251
- Calendar apps#149 of 194