Best Calendar Sync Tools in 2026 (Compared)

Do you juggle more than one calendar — Google for personal, Outlook for work, iCloud on your phone? Keeping them in sync is a chore. You miss meetings that live in only one calendar. You double-book yourself.

Who wrote this. Hetk wrote this list, and Hetk is one of the tools on it. We test our own product. We have not tested the other tools. What we say about them comes from their own public pages, and each fact has a link and the date we checked it. No vendor paid to be on this list, and none of the links here are affiliate links.

This guide compares calendar sync tools for 2026 on price, plan limits, which calendars they support, and privacy options.

Best calendar sync software at a glance

If you want the short version: Hetk at $15/year is the lowest-priced paid tool on this list. It covers Google Calendar, Outlook, and iCloud, syncs both directions, and can strip event details when syncing into a calendar other people can read.

The others fit specific cases. OneCal ($60–300/yr) if you want more calendars on one plan. CalendarBridge ($48–384/yr) if you want booking links in the same tool. SyncThemCalendars ($47.88–215.88/yr) if you need many sync relationships. Zapier if calendar sync is one step in a larger automation. OGCS is free and open-source, but it runs on Windows and covers only Outlook and Google. Native ICS subscriptions cost nothing and work anywhere, but they are one-way and read-only.

Hetk gives you 21 days with every feature and no credit card; after that it is $15/year.

How did we compare these tools?

Hetk: tested by us. An automated test suite runs every sync direction across Google, Outlook, and iCloud, plus the privacy modes, recurring events, and deletions. It uses real Google Calendar, Microsoft 365, and Apple iCloud accounts, not mocks.

Everyone else: as advertised. We did not run the other tools. Their rows hold only what each vendor says on its own public page: price, plan limits, trial length, supported calendars, and privacy options. Each section ends with a link to that page and the date we read it. We make no claim about how fast or how well a rival syncs.

How do the calendar sync tools compare?

Rival prices and limits were read on each vendor’s own page on 26 October 2026. They may have changed since.

The tools, one by one

Hetk — lowest price for all three providers

Price: $15/year Personal, $50/year Professional ($10/$35 early adopter pricing)

Providers: Google Calendar, Microsoft Outlook, Apple iCloud

Key features:

• Two-way sync between any of the three providers
• Privacy controls (Replace the details with “Busy”, Flag the copy as private, title templates)
• Automatic duplicate detection
• Up to 3 sync pairs (Personal) or 8 sync pairs (Professional)
• 21-day free trial with full feature access, no credit card

Setup: Sign in with Google. Add your other providers (Outlook, iCloud). Pick the calendars to sync, choose a direction (one-way or two-way), and set privacy options if you want them.

Work accounts: A Microsoft 365 or Google Workspace account at work may need your IT admin to approve Hetk first. If Microsoft shows “Need admin approval”, see the admin consent guide.

How sync works: Google and Microsoft push a notification when an event changes. Changes in Google Calendar and Outlook usually arrive within seconds, through push notifications. A safety check runs every 15 minutes in case a notification is missed. Apple iCloud has no push. Hetk checks iCloud every 5 minutes, and less often for a calendar that has been quiet. See how sync timing works.

Privacy in action: Turn on the Replace the details with “Busy” setting and synced events show up as plain “Busy” blocks. The title, description, location, and guest list are all stripped out. That’s handy for pushing personal events onto a work calendar, or for keeping client details to yourself.

Mobile: There is no Hetk app. Hetk works in the cloud, so synced events show up in whatever calendar app is on your phone.

Pros:

• Lowest paid price on this list ($15/year; the next, SyncThemCalendars Basic, is $47.88/year)
• Covers Google, Outlook, and iCloud
• Privacy controls for sensitive schedules
• Sync is checked by an automated test suite against real accounts

Cons:

• Newer product (founded 2025), built by one person
• No scheduling or booking pages
• No team plans; it is for individuals

Best for: One person with calendars on more than one provider, such as Google for personal and Outlook for work.

Not ideal for: Teams that need booking pages, or anyone who needs an enterprise SLA.

OneCal — more calendars per plan

Price: $60–300/year ($60 for 2 calendars, $120 for 5, $300 for 50)

Providers: Google Calendar, Outlook, iCloud Calendar and CalDAV

What OneCal says it offers:

• Unlimited calendar syncs on every plan
• Privacy: Choose what event information to sync, on every plan
• Apps for iOS and Android
• A 14-day free trial

Compared with Hetk: OneCal costs more ($60–300/year against $15–50/year). Its top plan covers far more calendars, and it has its own mobile apps, which Hetk does not.

Best for: People who need many calendars on one plan, or who want a dedicated app.

For a deeper look, see the full Hetk vs OneCal comparison — or the OneCal alternative writeup if you’re weighing a switch.

CalendarBridge — sync plus booking links

Price: $48–384/year (Basic $48 for 2 calendars, Premium $96 for 5, Pro $384 for 8)

What CalendarBridge says it offers:

• Up to 10 booking links
• Privacy: Control which event details sync (all details, just busy, or in between)
• Apps for iPhone and Android
• Sync speed, in its own words: “Events typically update in under a minute”
• A 7-day free trial

Compared with Hetk: CalendarBridge costs more, most of all on the Pro tier ($384/year). You get booking links in the same tool, which Hetk does not have.

Best for: People who want calendar sync and booking links in one tool.

For a deeper look, see the full Hetk vs CalendarBridge comparison — or the CalendarBridge alternative writeup if you’re weighing a switch.

SyncThemCalendars — many sync relationships

Price: $47.88–215.88/year (Basic $47.88 for 5 sync relationships, Premium $95.88 for 16, Professional $215.88 for 36)

Providers: Google, Outlook and Apple iCloud

What SyncThemCalendars says it offers:

• Plans metered on sync relationships, not on calendars
• Privacy: Hide event details behind a Busy block
• A 14-day free trial

Compared with Hetk: Its top plan allows more sync relationships (36) than Hetk Professional (8). Its entry plan costs more: Hetk Personal at $15/year is 69% below $47.88/year.

Best for: People who need many distinct sync relationships.

For a deeper look, see the full Hetk vs SyncThemCalendars comparison.

Zapier — an automation platform, not a sync tool

Price: Free for 100 tasks a month; Professional from $19.99/month billed annually ($239.88/year) or $29.99/month billed monthly

What it is: Zapier connects apps with “Zaps”: when something happens in one app, do something in another. It is not built as a calendar sync tool.

What that means for calendars: Zapier’s Google Calendar triggers each fire one way, and new or changed events (“New or Updated Event”) are a separate trigger from deleted ones (“Event Cancelled”). To keep two calendars matched you build one Zap per direction, plus more if deletions should carry across. Zapier counts “any successful action” as a task, so each event a Zap copies uses up part of your monthly allowance.

Compared with Hetk: Zapier’s paid plan starts at $239.88/year against Hetk’s $15/year. It can do far more than calendars.

Best for: People who already use Zapier and want calendar events to trigger other things, such as a chat message or a task.

Not ideal for: Anyone who only wants two calendars kept in step.

Zapier pricing and task limits checked 26 October 2026 on Zapier's pricing page. Plans may have changed since. Triggers checked 26 October 2026 on Zapier’s Google Calendar page; task counting on Zapier’s help centre.

For a deeper look, see Hetk vs Zapier calendar sync.

OGCS (Outlook Google Calendar Sync) — free, Windows only

Price: Free and open-source

Providers: Outlook and Google Calendar. No iCloud.

What the project says it offers:

• Runs on Windows, installed or portable
• Sync direction: one-way in either direction, or two-way
• Automatic syncs on a set frequency, including push-sync from Outlook
• Privacy: Can obfuscate custom words and force synced items to private

Compared with Hetk: OGCS costs nothing and runs on your own PC, so no outside service holds your calendar access. It only syncs while that Windows PC is running it, and it does not cover iCloud. Its page names one maintainer and asks for donations; it lists no paid support (checked 26 October 2026).

Best for: Windows users who sync only Outlook and Google and want a free, open-source tool.

Not ideal for: Anyone on Mac or Linux, or anyone using iCloud.

Native ICS subscriptions — the free DIY route

Price: Free (built into calendar apps)

How it works: You subscribe to a calendar URL in Google Calendar, Outlook, or iCloud. The file behind that URL is an iCalendar (.ics) feed, the open standard every major calendar app can read.

Setup: Copy a calendar’s ICS URL and paste it into your other calendar app’s “Add from URL” field.

How it updates: The subscribing app fetches the feed on its own schedule, not when an event changes. So new events show up late.

Limits:

• One-way only
• Read-only: you cannot edit the subscribed events
• No privacy controls beyond what the feed’s owner chose to publish
• Anyone with the URL can read the feed

Best for: Viewing a calendar you do not own, such as a sports schedule or public holidays. It is not a way to keep your own calendars matched.

Which calendar sync tool is right for you?

“I want the cheapest option”

Hetk Personal ($15/year)

At $15/year, Hetk is the lowest-priced paid tool on this list. You get two-way sync and privacy controls. The 21-day free trial lets you try before committing. If you only sync Outlook and Google on a Windows PC, OGCS is free.

“I use Google and Outlook and want something simple”

Hetk Personal ($15/year)

Hetk is built for exactly this. Sign in, pick your calendars, and choose a direction. On a work account your IT admin may need to approve it first; the admin consent guide explains how.

“I need booking links too”

CalendarBridge

CalendarBridge lists booking links on its plans. Hetk has no booking features and no team plans; it is for individuals.

“I use all three providers (Google, Outlook, iCloud)”

Hetk Personal ($15/year)

Hetk is the lowest-priced tool here that covers all three. OneCal, CalendarBridge and SyncThemCalendars list iCloud too, at a higher price (OneCal, CalendarBridge, SyncThemCalendars, checked 12 October 2026). The free options fall short: OGCS syncs only Outlook and Google, and plain ICS subscriptions are one-way.

“I need complex automation alongside sync”

Zapier (if no alternative fits)

Use Zapier if you need calendar events to trigger other things (chat messages, task creation, and so on). For plain calendar sync it is more than you need.

“I want to avoid cloud services”

OGCS (free, desktop only)

OGCS is free, open-source, and runs on your own PC. You are limited to Windows, Outlook, and Google.

So what’s the best calendar sync tool in 2026?

We make Hetk, so weigh this as our view. For one person with calendars on two or three providers, Hetk at $15/year is the lowest-priced paid option here, and it covers Google, Outlook, and iCloud with privacy controls. The 21-day free trial needs no credit card.

If you need booking links, more calendars on one plan, or a dedicated mobile app, look at CalendarBridge or OneCal and expect to pay more — $60–300/year for OneCal against Hetk’s $15–50.

We have only tested Hetk. Try the free trial of any tool you are weighing before you pay.

Every Hetk comparison page

Dedicated sync tools

• Hetk vs CalendarBridge · CalendarBridge alternative · CalendarBridge pricing
• Hetk vs OneCal · OneCal alternative · OneCal pricing
• Hetk vs SyncThemCalendars

Scheduling and AI planning tools

• Hetk vs Reclaim.ai · Reclaim alternative
• Hetk vs Motion
• Hetk vs Clockwise
• Hetk vs Morgen
• Hetk vs Calendly

Calendar apps and DIY routes

• Hetk vs Fantastical
• Hetk vs the built-in Outlook–Google sync
• Hetk vs Zapier calendar sync

Or browse all comparisons.

Related

• How to sync iCloud Calendar with Google Calendar
• How to subscribe to an ICS calendar in Google Calendar
• How to sync Google Calendar with Outlook