Compared August 2026 · every price and feature below was checked against OneCal’s own site on 28 August 2026. These change — check the OneCal site before deciding.
Multi-calendar sync with booking links, for people who live in Google and Outlook.
OneCal is a scheduling product. Calendar sync is one part of it; booking links and a unified view across accounts are the rest. If your working life spans Google and Outlook and you want other people to book time with you, that is a real product and Calendar Mirror is not competing for the job.
Calendar Mirror is a utility. It copies one calendar into another on an Apple device you already own, for $2.99 once, with no account. If you are on iPhone and Mac and all you need is the copy, OneCal's subscription buys features you would not use.
| Calendar Mirror | OneCal | |
|---|---|---|
| Price | $2.99 once · free from source | $5, $10 or $25 per user / month; $60, $120 or $300 annually |
| Account required | None — nothing to sign up for | Yes, with OAuth to each calendar account |
| Where your calendar goes | Nowhere. It never leaves the device. | To OneCal's servers, which hold the connection |
| Platforms | iPhone, iPad, Mac | Web, plus iOS and Android apps |
| Calendar sources | Anything the device can see — iCloud, Google, Exchange, CalDAV, subscribed ICS feeds | Google, Outlook and iCloud |
| Sync speed, Apple calendars | Detects changes within seconds on macOS (standalone build) | “about every 10 minutes” for iCloud, per their docs |
| Sync speed, Google / Outlook | Whatever the device's own account refresh is | Real-time, per their docs |
| Booking / scheduling links | No | Yes — unlimited one-on-one and collective links |
| Unified calendar view | No | Yes |
| Per-event override | Yes — #nomirror, #private, #public in an event's notes | Not published |
| Duration filters | Yes — skip events shorter or longer than N minutes | Not published |
| Team, admin, SSO | No | Yes, on the higher tiers |
OneCal reads iCloud, but its own documentation puts detection at about ten minutes, because Apple gives third parties no push API. Google and Outlook, by contrast, are real-time for them.
You can move iCloud onto the fast path. Mirror the iCloud calendar into a Google calendar on your Mac — Calendar Mirror notices the change within seconds — and let OneCal watch the Google copy in real time. It also means iCloud events can feed OneCal’s booking links, which is the part Calendar Mirror will never do itself.
Bridging adds a hop: Calendar Mirror writes the copy on your device, and the other service then reads that copy on its own schedule. It needs the destination account set up on your Mac or iPhone, and the copy is one-way, like every Calendar Mirror mirror.
None of these are coming later. If you need one of them, buy something else:
One purchase covers iPhone, iPad and Mac. Calendar Mirror is not affiliated with OneCal in any way, and this page is written by Calendar Mirror’s author.