Sync Data Using MobileMe or Google

As soon as your collection of Apple devices running OS X or iOS expands to two or more, the issue of syncing is bound to come up. You'll want most or all of the important personal data on your first device--e-mail, calendars, contacts, notes, and more--to be identical on your second device, and you'll want to be able to update the data in either place and have the changes reflected in the other.

That basic scenario isn't difficult to achieve, but it gets more complicated as the number of variables increases. Add more data types, more devices, different operating systems and versions, cloud-based services, push sync, and other niceties, and pretty soon you have an inscrutable tangle of connections.

So, to keep the process as straightforward as possible, here are some ground rules for this article:

* I'll assume your Mac(s) run OS X 10.6 Snow Leopard and mobile device(s) run iOS 4 (but see "What About iOS 3 and OS X 10.5?" if your device uses an older operating system).

* I talk only about syncing Apple's applications--Mail, Address Book, iCal, Safari, and so on--not third-party applications, which add numerous complexities.

* This guide covers e-mail, contacts, calendars, to-do items, notes, and browser bookmarks--but not other data types you may want to sync.

* I discuss syncing data only for a single user between multiple devices that person uses--not syncing data between multiple users (but see "Other sync options" for some suggestions about multi-person synchronization).

* The focus here is primarily on just two methods of syncing all your data: using Apple's MobileMe service ($99 a year for individuals, $149 for the five-user Family Pack, although you can usually find it for less from places such as, and using a variety of free services from Google--Gmail, Gmail Contacts, Google Calendar, and Gmail Tasks. (For help deciding which to use, see "Choosing between MobileMe and Google.")

I'll also offer one general piece of advice at the outset: Instead of turning on all types of syncing on all your devices at once, concentrate on getting just one type of data syncing between two devices, gradually add the rest of your devices, and then repeat the procedure for each data type.

Syncing with MobileMe

MobileMe is best known for its highly visible services such as e-mail and iDisk, but one of its most impressive talents is keeping many kinds of data in sync among multiple Macs and iOS devices. Because Apple's servers function as both mediator and online storage for all your synchronized data, you can also access your information in a Web browser on almost any Internet-connected device at And the entire process is easy to set up, too, although not without occasional glitches.

Before you start experimenting with changes in your sync setup, I recommend that you back up your Mac--most crucially your calendar and contact data, which are especially vulnerable to accidental change or deletion. If you already use Time Machine or a cloning utility such as Super Duper ($28), you're all set. Otherwise, to back up the contents of the OS X Address Book, open Address Book (in /Applications), choose File -> Export -> Address Book Archive, enter a name and choose a location for the exported data (preferably on a different disk), and click Save. To back up your iCal calendars, open iCal (in /Applications), choose File -> Export -> iCal Archive, enter a name and choose a location for the exported data, and click Save. If you're using an iPhone, iPad, or iPod touch, attach it to your Mac using its USB cable or dock and allow it to sync before proceeding.

Basic setup On a Mac, open the MobileMe pane of System Preferences. If the window shows Member Name and Password fields, fill them in and click Sign In. Next, click the Sync tab and select the Synchronize With MobileMe checkbox. The pop-up menu provides several options for synchronization frequency. The default choice, Automatically, is what Apple recommends (as do I). For most data types, this setting means that when data changes on your Mac, it's pushed to Apple's servers immediately, and when changes are made elsewhere, they're retrieved from Apple's servers quickly--usually within seconds. (Some types of data, including keychains and preferences, which I don't cover here, follow a more relaxed automatic syncing schedule.)

You'll also need to select the checkbox for each type of data you want to sync. For our purposes, that means (at least) Bookmarks, Calendars, Contacts, and Notes. Read on for further details, but remember that it never hurts to activate and test these one at a time. Finally, make sure Show Status In Menu Bar is selected; that displays the Sync menu (an icon with two arrows arranged in a circle) in your menu bar, which will come in handy later on.

On an iOS 4 device, if you don't already have a MobileMe account set up, tap Settings -> Mail, Contacts, Calendars -> Add Account -> MobileMe, enter your credentials, and tap Next. After iOS verifies your information, it displays a series of services you can turn on or off, but you can leave everything set at its default for now, and simply tap Done.

E-mail MobileMe addresses the problem of syncing e-mail in two different ways. First, your MobileMe e-mail account uses IMAP (Internet message access protocol). With IMAP, the mail server always contains a master copy of all your messages and mailboxes--including sent and filed e-mail (not to mention status flags such as read/unread, forwarded, and replied to). So, set up multiple clients using the same credentials, and after they've had time to sync, they'll show exactly the same mailboxes and messages. (Microsoft Exchange ActiveSync is a different protocol that offers similar benefits.)

Second, MobileMe lets you sync the settings for all your accounts (not just MobileMe) between devices, although it doesn't sync the messages themselves. If all your accounts are of the IMAP and Exchange varieties, syncing is simple because MobileMe handles syncing account settings, while Mail syncs the messages themselves with the servers. (If you have any POP accounts, syncing messages between Macs is more involved; read more in "Sync your e-mail messages.")

In the Sync view of the MobileMe pane of System Preferences are two checkboxes having to do with Mail: Mail Accounts; and Mail Rules, Signatures, And Smart Mailboxes. When you select Mail Accounts on two or more Macs, OS X synchronizes the basic settings (such as server addresses and e-mail addresses) for all your e-mail accounts between them. This setting does not sync your passwords, though; if you store your Mail passwords in your Keychain, you can select Keychains, separately, to sync those too. The result is that, for IMAP and Exchange accounts, both Macs will download and display identical copies of the messages from the respective servers. (Messages stored locally in "On My Mac" mailboxes don't sync via MobileMe.)

When you select Mail Rules, Signatures, And Smart Mailboxes, those portions of Mail's preferences sync between the Macs. This is usually helpful, but if two Macs have different sets of active accounts or local mailboxes, some of your rules, signatures, and smart mailboxes may not work correctly.

Although MobileMe syncs Mail settings between Macs, it doesn't sync Mail settings to your iOS devices; instead, iTunes does that job. With your iOS device attached via USB, open iTunes, select your device in the Devices section of the sidebar, and click the Info tab. Select Sync Mail Accounts, along with each e-mail account on your Mac for which you'd like to transfer settings to your iOS device. Then click Sync.

Once you've done this, go to Settings -> Mail, Contacts, Calendars on your iOS device, tap your MobileMe account, and make sure the Mail switch is set to On. Repeat this procedure for each server-based account you want to sync.

In addition--still on the Mail, Contacts, Calendars screen--make sure Fetch New Data is set to Push if you want data such as e-mail, calendars, and contacts to update immediately on your iPhone when they change on another device. (If not, tap Fetch New Data and tap the switch next to Push.) Push decreases battery life; if that's your top concern, leave Push turned off and choose the frequency with which you want to fetch new data.

Assuming your settings are correct, your Internet connection is active, and you've waited long enough for any messages on the server to download to each of your Macs, your e-mail should now be in sync. On iOS devices, Mail doesn't automatically download all the messages in all your mailboxes; it downloads the contents of your Inboxes (up to the limit specified in Settings -> Mail, Contacts, Calendars -> Show), and then it downloads the contents of any individual mailbox (again, up to the limit you set) when you select it.

Contacts To sync your contacts via MobileMe, make sure the Contacts checkbox is selected in the Sync view of the MobileMe pane of System Preferences. OS X then syncs all the local ("On My Mac") contacts between your Mac(s) and Apple's servers. Contacts on LDAP servers, or in CardDAV or Exchange 2007 accounts, don't sync via MobileMe; you must set up these accounts separately on each device.

To enable over-the-air contact syncing for your MobileMe account on an iOS device, tap Settings -> Mail, Contacts, Calendars, tap your MobileMe account, and make sure Contacts is set to On. To sync with Exchange accounts as well, tap their names in the list of e-mail accounts and likewise ensure that Contacts is turned on.

Calendars MobileMe can sync the calendars you created on your Mac(s) in iCal with Apple's servers, to other Macs, and to your iOS devices. Apple's newly revised calendar system for MobileMe uses the industry-standard CalDAV protocol for syncing calendar data (just as Google does) rather than relying on a proprietary mechanism as MobileMe did in the past. This should make calendar syncing more robust and flexible.

However, because the new Calendar is significantly different from the old one and requires some extra set-up steps, Apple hasn't switched everyone over automatically. To use the new CalDAV-based system, those who didn't participate in the beta testing must sign in to the MobileMe Web site, go to the Calendar application, click Upgrade Now, and follow the directions Apple provides there. Then continue with the following steps.

On each Mac, make sure Calendars is selected in the Sync view of the MobileMe pane of System Preferences. Note that MobileMe syncs only local ("On My Mac") calendars and read-only calendars to which you've subscribed. (Subscribed calendars appear only on other Macs and iOS devices, not on the MobileMe Web site.) If you've set up any server-based calendar accounts, such as CalDAV or Exchange 2007, these won't sync via MobileMe; you'll have to configure such accounts individually on each device.

On an iOS 4 device, go to Settings -> Mail, Contacts, Calendars -> Your MobileMe Account and make sure Calendars is turned on. After turning it on initially, you may see a prompt asking how to treat existing calendar data. If so, "Merge with MobileMe" is the correct choice.

To-Do items OS X considers to-do items, or tasks, to be calendar data, and therefore they appear in iCal. (If your tasks aren't visible, choose View -> Show To Do List or press Command-Option-T.) Starting with OS X 10.5, Mail can also create and display to-do items, using the same calendars as iCal. To create a new to-do item in Mail, click the To Do button in the toolbar; tasks then appear in the To Do list under Reminders in the sidebar. (I discuss the use of to-do items, as well as notes, in Mail in "Master Mail's reminders.")

As a result, as long as you sync Calendars as described above, your to-do items will come with them. You can then access them in the Calendar app on the MobileMe Web site (if you don't see your tasks, choose Show To Do List from the gear-shaped pop-up Action menu), or in iCal on another Mac.

Unfortunately, for reasons I've never understood, Apple provides no way to access to-do items on an iOS device. They don't appear in the Calendar app, and there's no separate Tasks app either. If you want to sync to-do items with your iOS device, you must turn to third-party software (see "Other sync options").

Notes Along with to-do items, Mail lets you store notes--lists, thoughts, and other random snippets of information. You can create a note by clicking the New Note button in Mail's toolbar; it then appears in the Notes list under Reminders in the sidebar (and potentially in your Inbox as well, depending on your preferences). In iOS 4, Mail's notes can sync wirelessly with the Notes app on your iOS device too (see "Syncing iPhone notes to MobileMe" for more details). However, there's a catch or two.

First, you must make sure note syncing is turned on for your MobileMe account. To do this, tap Settings -> Mail, Contacts, Calendars -> Your MobileMe Account, and verify that Notes is set to On. Second, you must make sure your MobileMe account is the default location for creating new notes: back on the Settings -> Mail, Contacts, Calendars screen, scroll to the bottom and check the Default Account setting under "Notes." If it's not your MobileMe account, tap it and select that account. Finally, you can't move notes between accounts, so any notes you previously stored locally on your iPhone, or in another account, must be re-created in your MobileMe account for syncing to work correctly.

One significant drawback to this way of syncing notes is that although you can see them on the MobileMe Website (in the Notes mailbox within the Mail app), you can't edit them there.

Bookmarks If you select the Bookmarks checkbox in the Sync view of MobileMe System Preferences on each of your Macs, OS X syncs Safari's bookmarks between them; no further configuration is needed. On an iOS device, tap Settings -> Mail, Contacts, Calendars -> Your MobileMe Account and make sure the Bookmarks switch is set to On. Bookmark syncing via MobileMe applies only to Safari (on either OS X or iOS). See "Other sync options" for a suggestion about syncing bookmarks across Mac browsers.

Troubleshooting Because syncing is inherently complex, errors and unexpected behavior can occur--especially if you frequently go without Internet access on one or more devices. A complete troubleshooting guide would require many pages, but I can give you a few quick tips:

* Set data change alerts. MobileMe can optionally notify you if a pending sync would change more than a small amount of data. This warning can help you avoid problematic syncs (click Cancel when you see the alert, and reset your sync data as in the next tip). To adjust this behavior, open the MobileMe pane of System Preferences, click the Sync tab, and click Advanced. At the bottom of the dialog that appears, select Show Alert When X Of The Data On This Computer Will Be Changed, and choose an amount (I suggest the More Than 25% option) from the pop-up menu.

* Resolve sync conflicts. In certain situations--particularly when one of your devices is offline for a while--you could end up changing a particular contact, event, bookmark, or other data on two different devices in between syncs. When this happens, OS X doesn't know which version you want to use, so it presents a Conflict Resolver dialog. Click Review Now to see what items are in conflict, click the one you want to use, and then (if there's more than one), click Continue and repeat the process as needed.

* Reset sync data. If you know or suspect that your data has gotten badly out of sync, you can reset it--that is, replace the synced data on your Mac with the copy that's on the MobileMe servers or vice-versa. To do this, open the MobileMe pane of System Preferences, click the Sync tab, and click Advanced. At the bottom of the dialog that appears, click Reset Sync Data. Then choose the type of data to replace (or All Sync Info, to replace everything) from the pop-up menu at the top, and choose the direction in which the replacement should occur by clicking one of the arrows. Click Replace, and a new sync begins immediately.

* Use the Sync menu. The Sync menu that you enabled earlier lets you force a sync to occur immediately (choose Sync Now) or stop a sync in progress (choose Cancel Sync). Starting in Snow Leopard, it also has some hidden features. Hold down the Option key while clicking the menu, and you'll see additional commands. Choose Open Sync Diagnostics to collect data from your system about a problematic sync and send it to Apple for analysis; or, for problems not solved by resetting sync data, choose Reset Sync Services. This command leaves your data intact but erases your sync history, which can solve certain tricky sync problems.

Syncing with Google

For e-mail, contacts, and calendars, Google's services offer features that closely parallel what MobileMe has--and without costing you a cent. You can sync your data between multiple computers and the cloud; you can access it in any Web browser; and you can choose over-the-air push synchronization for mobile devices. For other types of data (to-do items, notes, and bookmarks), the syncing story is much different, but with some effort, you can achieve much of what MobileMe offers, at a fraction of the price.

Be aware, though, that because of differences between the way Google stores data and the ways Address Book and iCal do, some items (including Address Book groups and the "floating" time zone in iCal) don't sync at all, while others are subject to occasional mutilation as they try to fit into Google's categories, and vice-versa.

Basic setup Before you begin, if you haven't already done so, back up all the contact and calendar data on your Mac, as discussed earlier. If you're using Google Apps (for a custom domain name), also make sure you've enabled Google Sync for your domain by following Google's instructions. And, if you use an iOS device, be sure you sync it with your Mac using its existing settings.

E-mail If you're content to use a browser for e-mail, then syncing is a non-issue. However, if you prefer to use a conventional e-mail client such as Mail in OS X or iOS, you can set it up to access your Gmail account. Gmail lets you connect using POP, IMAP, or Exchange ActiveSync protocols, but only the latter two automatically keep all your e-mail in sync across devices. (And, although you can use either protocol under iOS, Google doesn't currently support connecting from OS X via Exchange ActiveSync. But it's no problem to use Exchange ActiveSync under iOS and IMAP, for the same account, under OS X.)

Before you can access your Gmail account from Mail, you must turn on IMAP support. To do this, go to (or, if you use Google Apps for a custom Gmail domain name, go to the URL you normally use) and log in. Click on the Settings link, click Forwarding And POP/IMAP, and then, in the IMAP Access section, select the Enable IMAP checkbox. Click Save Changes.

Next, in Mail on OS X, choose Mail -> Preferences, click Accounts, and click the + (plus) icon. Enter your full name, your Gmail address (for Google Apps users, include the @ sign and the domain name), and your password, and click Create. Mail automatically configures the account to use IMAP.

On an iOS 4 device, the easiest way to configure Gmail to use IMAP is to tap Settings -> Mail, Contacts, Calendars -> Add Account -> Gmail, enter your credentials, tap Next, and then (after your credentials are verified) tap Done.

However, you can also access your Gmail account on your iOS device using Exchange ActiveSync, which gives you the option of push e-mail and automatically syncs your Google calendars and contacts without any further hassles. The instructions for setting up your iOS device to access Gmail using Exchange ActiveSync are somewhat lengthy, but Google spells out all the details on its Website.

Contacts in OS X To sync Address Book with Gmail Contacts' My Contacts list, open Address Book, choose Address Book -> Preferences, click Accounts, select On My Mac in the Accounts list on the left, and then click the Account Information tab. Select the Synchronize With Google checkbox, and then click Configure. If you're setting up Google syncing for the first time, an alert appears explaining about the synchronization process; read this and click Agree. Then, in the dialog box that appears, enter your Gmail address in the Google Account field and your password in the Password field, and click OK. You may see a warning that Address Book can't verify the identity of the server; if so, click Continue.

Next, make sure the Sync menu appears in your Mac's menu bar, as discussed earlier. Choose Sync Now from the Sync menu. During the initial sync, if the Conflict Resolver window appears, click Review Now, decide which version of each contact to use, and then click Sync Now. After the first sync, OS X should sync changes once per hour, although you can sync manually at any time by using the Sync Now command.

Calendars in OS X To sync iCal with Google Calendar, open iCal, choose iCal -> Preferences, click on Accounts, and click the plus (+) button. Choose Google from the Account Type pop-up menu, and enter your full e-mail address (whether ending in or your custom domain) in the Email Address field and your password in the Password field, and click on Create. You may see a warning that iCal can't verify the identity of the server; if so, click Continue. Your primary Google calendar then appears in iCal. To sync additional Google calendars, click the Delegation tab in the Preferences window and select the Show checkbox for one or more calendars.

This procedure syncs existing Google calendars with iCal, but not the other way around. To move your existing iCal data into Google Calendar, find one of your calendars in Google on the left side of the screen, click the Settings button beneath it, click Import Calendar next to the Create New Calendar button, and then in the dialog box that appears, click Browse, navigate to the iCal backup file you created earlier, and select it. In the Import Calendar dialog box, select the calendar to which you'd like to add the events (if you have more than one) from the Calendar pop-up menu and then click the Import button to bring your calendar info in.

By default, iCal syncs with Google Calendar every 15 minutes (or when you add, delete, or change an event on your Mac), but you can change the interval if you prefer by clicking on the Account Information tab in the Preferences window and choosing a new value from the Refresh Calendars pop-up menu.

Calendars and contacts in iOS To sync contacts and calendars on your iOS device, go to Settings -> Mail, Contacts, Calendars and tap Add Account at the bottom of the Accounts list. Tap Microsoft Exchange, enter the full e-mail address associated with your Google account in the Username field and your password in the Password field; leave Domain blank. Tap Next. If an Unable To Verify Certificate message appears, tap Accept. In the Server field, enter, and tap Next again. Make sure Contacts and Calendars are turned on (plus Mail, if you want to sync your Gmail e-mail using Exchange ActiveSync) and tap Done. When prompted to choose how to handle existing data, tap Delete. Synchronization begins momentarily, and everything happens wirelessly.

To-Do items Whereas Apple considers to-do items to be calendar data, in Google's world, Tasks (to-do items) are part of Gmail, not Google Calendar. Partly because of this difference, and partly because Google doesn't use a standard mechanism (such as WebDAV) to provide access to task data, there's no direct way to synchronize your iCal to-do items with Gmail Tasks.

However, there is a third-party Mac application called iGTask for iCal that can sync to-do items between iCal and Gmail Tasks (see "Other sync options"). Alternatively, you can skip iCal altogether and simply manage all your tasks in Gmail Tasks in a Web browser.

On iOS devices, Apple provides no way at all to sync or view to-do items. However, if you visit in Safari on your mobile device, Google presents you with a special version of your task list that's optimized for small screens. This method doesn't store your tasks for offline access, but in other respects it's a good way to access Gmail Tasks on your mobile device.

Notes Google has no service that corresponds closely to Apple's notion of notes. However, if you use IMAP to access your Gmail account, you can see (though not edit) notes you create in Mail, or in the iOS Notes app, in Gmail (marked with a Notes label).

If you set up your Gmail account to use IMAP (as is the case when you tap Gmail when choosing an account type), go to Settings -> Mail, Contacts, Calendars -> Your Gmail Account and tap the switch next to Notes to turn it on.

However, if you use Exchange ActiveSync to access your Gmail account, the Notes option doesn't appear. Therefore, to get this capability you must set up an additional account on your iOS device. Tap Settings -> Mail, Contacts, Calendars -> Add Account, and then Gmail. Enter your Gmail credentials and then turn on Notes but turn off Mail and Calendars (to avoid duplicate data on your device).

Bookmarks Unlike MobileMe, Google has no bookmark-syncing component. For an alternative, see "Other sync options."

[Senior contributor Joe Kissell is the senior editor of TidBits and the author of the e-book Take Control of MobileMe (TidBITS Publishing, 2010)].

Subscribe to the Best of PCWorld Newsletter