Can you sync Google Calendar and Outlook two-way for free?

Only partially. The free ICS-subscription method is one-way and can lag 12–48 hours. True real-time, two-way sync needs a dedicated service; LeapSync starts at $4/month with a free 14-day trial.

How fast is real-time sync?

With a webhook-based tool like LeapSync, changes appear in the other calendar in under ~5 seconds. Polling-based automations (Zapier) take 1–15 minutes; ICS subscriptions take hours.

Will syncing create duplicate events?

Not with a purpose-built tool. LeapSync tracks which mirror corresponds to which original, so edits update the existing copy rather than creating new ones. Naive two-way automations are what cause duplicate loops.

Do I need to install software?

No. LeapSync runs entirely on the web (on Cloudflare's edge). You connect Google and Microsoft once in your browser and it syncs server-side, even when your computer is off.

Can I see the synced calendar on my iPhone?

Yes. LeapSync publishes a private read-only Apple/ICS feed you subscribe to in Apple Calendar by scanning a QR code — no Apple ID password needed. Edits still happen in Google or Outlook.

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How to sync Google Calendar with Outlook (two-way, in real time)

Updated 2 June 2026 · LeapSync team

A laptop and phone syncing calendars across a green link — how to sync Google Calendar with Outlook two-way

Short answer: Google Calendar and Microsoft Outlook have no built-in two-way sync. Their native options only display one calendar inside the other, read-only, and an ICS subscription can lag 12–48 hours. To get true real-time, two-way sync — where an event created or edited in either calendar appears in the other within seconds — you need a dedicated sync service such as LeapSync. Connect both accounts once on the web, pick the direction, and you're done in about two minutes. No software to install.

Why Google and Outlook don't sync on their own

Google Calendar and Microsoft 365 / Outlook are competing ecosystems, so neither builds genuine sync into the other. What they offer instead:

ICS subscription — paste your Google calendar's secret .ics URL into Outlook (or vice-versa). It's free, but one-way and slow: Outlook refreshes subscribed calendars on its own schedule, often every few hours up to a day or two. Edits never flow back.
Import / export — a one-time dump of events. Not sync at all; it goes stale the moment either calendar changes.
Automation tools (Zapier, Power Automate) — can copy events, but they poll on an interval (typically 1–15 minutes), break on recurring events, and get expensive once you sync in both directions.

The options compared

Method	Direction	Speed	Cost
Native ICS subscribe	One-way	12–48 hours	Free
Manual import/export	One-time	Stale instantly	Free
Zapier / Power Automate	One- or two-way	1–15 min (polling)	Per-task fees
Dedicated sync tool (LeapSync)	Two-way	Under ~5 seconds	From $4/mo

How to set up real-time two-way sync in 2 minutes

Create a free LeapSync account at app.leapsync.app/signup — magic-link or "Sign in with Google / Microsoft", no password.
Connect your Google Calendar. You authorise on Google's own screen; LeapSync only requests calendar read/write — never email, contacts, or files.
Connect your Microsoft 365 / Outlook.com account the same way.
Choose the calendars and direction — two-way, or one-way if you prefer. LeapSync mirrors events between them and keeps them matched.

From then on, an event you add or change in either calendar shows up in the other, typically in under five seconds, thanks to push notifications from Google and Microsoft (plus an hourly safety sweep so nothing is ever missed). Want it on your iPhone too? LeapSync publishes a private, read-only Apple/ICS feed you subscribe to by scanning a QR code — no Apple ID password required.

How to avoid duplicate events

Duplicates are the classic failure of DIY sync — run two one-way automations at each other and every event echoes back and forth forever. A purpose-built tool fixes this by tracking which mirrored event corresponds to which original, so an edit updates the existing copy instead of creating a new one. If you've already made a mess with Zapier or manual imports, clear the duplicated copies once, then let a single two-way sync own the relationship.

2026 heads-up: Microsoft is retiring Exchange Web Services (EWS) for Exchange Online on 1 October 2026; Microsoft Graph becomes the only supported API for Microsoft 365 calendars. Older sync tools still on EWS will break. LeapSync is built on Microsoft Graph today, so your sync keeps working.

Stop double-booking yourself across Google and Outlook.

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Is two-way sync safe and private?

It depends on the provider, so check before you connect. LeapSync stores only what it needs to match events (IDs and timestamps) and does not keep your event titles, descriptions, or attendee lists in its database; access tokens are encrypted at rest with AES-256-GCM. You can disconnect at any time, and token data is deleted within 30 days.

Frequently asked questions

Can you sync Google Calendar and Outlook two-way for free?: Only partially. The free ICS-subscription method is one-way and can lag 12–48 hours. True real-time, two-way sync needs a dedicated service; LeapSync starts at $4/month with a free 14-day trial.
How fast is real-time sync?: With a webhook-based tool like LeapSync, changes appear in the other calendar in under ~5 seconds. Polling-based automations (Zapier) take 1–15 minutes; ICS subscriptions take hours.
Will syncing create duplicate events?: Not with a purpose-built tool. LeapSync tracks which mirror corresponds to which original, so edits update the existing copy rather than creating new ones. Naive two-way automations are what cause duplicate loops.
Do I need to install software?: No. LeapSync runs entirely on the web (on Cloudflare's edge). You connect Google and Microsoft once in your browser and it syncs server-side, even when your computer is off.
Can I see the synced calendar on my iPhone?: Yes. LeapSync publishes a private read-only Apple/ICS feed you subscribe to in Apple Calendar by scanning a QR code — no Apple ID password needed. Edits still happen in Google or Outlook.