I dispense what might be called valuable insight to my friends, as well as in this public forum. My friends know the danger: they might become the topic of a column, which is true for my buddy Jeff, who left a bag containing his passport behind at a hotel. Fortunately, he had an AirTag in his bag. That was, however, just the beginning of the journey. (Jeff gave me permission to share his story.)¹

To avoid suspense, I’ll tell you that Jeff doesn’t have his bag back, but will soon.

Grate news

Jeff was out of town on business for a few days—he’s one of those nearly extinct creatures called a “full-time technology reporter“—and was carrying his passport to Texas not because it’s another country (it hasn’t seceded yet), but because he lacks a Real ID-upgraded driver’s license. He had a small bag with a few items, including the passport and an AirTag, that he didn’t need to carry, so he used the hotel safe. There have been many articles written about how unsafe hotel safes are, but it feels as if you’re in a decent hotel, it’s still another bar for someone to get through to steal your stuff.

Leaving in a bit of a rush, Jeff didn’t retrieve the bag from the safe. When he realized it wasn’t with him, thousands of miles later, he was peeved. Shouldn’t the “left behind” feature in Find My have alerted him? Find My showed the bag’s location, however. For some reason, it appeared as if it were in the hotel parking lot. I catastrophized with him, assuming it was stolen. He called the hotel, which said it wasn’t in lost and found.

A staff member went out, looked in the parking lot, and said the rough location was a grate—perhaps the bag had been stolen and someone had found the AirTag and dropped it through the slats? Which would imply that a hotel employee or a thief had managed to get into Jeff’s room after he left, open the safe, leave the hotel, and rummage through the bag in the parking lot before absconding.

That wasn’t the case (or valise). The hotel called back the next day. The previous staffer didn’t know, for some reason, that valuable left-behind items were tagged and placed in a safe in the basement, presumably below or near the parking lot. His bag, containing his passport and other items, would be sent back to him.

Jeff’s experience reveals several aspects of the Find My tracking system that you can take advantage of in advance or use if you’ve lost something or left it behind.

Don’t leave me!

Every device and item you have can be set to alert you when you “leave it behind.” I believe this setting is enabled by default, though Apple’s documentation isn’t clear on this point. All of my devices and items have it enabled, and Jeff found it was turned on for all his gear. Here’s how to check:

1. In a native Find My app, select the device (like a Mac) or an item (an AirTag or other Find My network item) in the list of such things.
2. On an iPhone, iPad, or Apple Watch, the action sheet appears. On a Mac, click the info (i) icon next to the item’s name on the map. In the upcoming version 27 operating system releases on all platforms, tap or click the More (…) button that appears when you select the device from the list.
3. Tap or click Notify When Left Behind, which should already show On. (In the 27 releases, tap or click When Left Behind.)
4. If disabled, turn it on.

Here’s a crucial detail: examine the “Notify me, except at” list. You can manually add to this set of locations (tap or click New Location). However, it primarily grows when you’re notified by an item or device being left behind, and then you tap or click in the notification to ignore it at that location. You are presented with the option to just exclude that item or device from that location or all of your equipment.

It’s very easy to approve that exclude-all button. (Jeff did not; his list didn’t include the hotel.) This can be convenient when you’re at a hotel, a friend’s house, or another location for a few days or frequently, and sometimes leave Find My-tracked stuff there. But once you ignore the location, you won’t get notified in the future. You can modify the list by hand, too.

Jeff may instead have been tripped up by the safe acting as a Faraday cage—a metal mesh or box that shields electromagnetic signals from passing through. The AirTag and other Find My items use Bluetooth to broadcast a rotating identifier at regular intervals.² If the safe blocked that signal, Jeff’s iPhone lost contact with the AirTag the moment the bag went in—a few days before he left. With no fresh separation between the phone and the item at departure time, the alert may have lacked the necessary trigger. Jeff was on the verge of sharing the location with the hotel when they found it.

Apple says this takes longer than the few days Jeff was on his trip: “You can see its last known location for up to seven days in the Find My app.” After seven days, the device or item’s location will appear as “No location found” or “Offline.” Jeff could see the item’s location, which made the lack of notification seem like a bug.

Now for the grate part (not great part): once Jeff’s bag was removed from the safe in his former room, it would have been carried through the hotel and detected by every iPhone, iPad, or Mac nearby. When it reached the hotel’s lost-and-found safe, the rough location would likely still be relatively close before it entered that particular Faraday cage. At which point, when Jeff looked at Find My, he saw it at (or under) the parking lot.

Sack attack

The hotel works with a service that handles the return. Jeff paid both a whopping and reasonable $60 to have it sent two-day air back to him. Fair enough! Unfair enough, days after he paid, the bag is still at the hotel (as I write this). Jeff will, of course, follow its progress via Find My.

[Got a question for the column? You can email glenn@sixcolors.com or use /glenn in our subscriber-only Discord community.]

I had a simple task that involved Apple Home. If you use Apple Home, you know what happened next. Tears, frustration, the arrival of batteries, paperclips pushed into hard-to-reach holes, many online searches, and—if you are lucky, as I was—success.

Siri, am I lazy?

My goal was straightforward: can I know if the garage door is open without going to look? Early in the pandemic, we occasionally forgot to close it. While there was a locked door between the garage and the house, it still felt like we were playing with fire, as someone could steal a bike or other lesser goodies from the garage.¹ The garage is on our basement floor (ground level on one half of the house), and the last thing I enjoy doing at night is walking downstairs before bed to check the door.²

I purchased an Eve Door & Window Contact Sensor to have this capability reported by Apple Home, joining a growing set of HomeKit devices, including our front-door deadbolt. Because of our old-style single-piece swing-up garage door, I had a heck of a time finding the right place and right adhesive to stick the sensor where it was close enough for the two components to register.

I spent enough time on the vagaries of physics and materials that I was probably more frustrated than I needed to be when I tried to make a workflow with the danged thing. An Automation wouldn’t work because I wanted an alert, not for the sensor to trigger other Home devices. A Shortcut should have worked, but after many hours of trying over weeks, I was unable to get anything reliable to happen. The Automation was quite simple: at 9 p.m., check the state of the sensor, and send me a message if the sensor shows Open rather than Closed. I left it in place and walked away for literally years.

After recently installing a back-driveway camera, I was determined to get this sensor online.³ First, I replaced the battery, which had died during my period of disinterest. The Eve sensor uses a weird, tiny battery: a 3.6V 1/2 AA (ER14250). After that arrived, using some better adhesive—thin-film 3M 468MP—I positioned the sensor pieces in a better location and more securely.

Now it should work! Except that after adding it, I saw Characteristic in red text on a pink background in Shortcuts. Some online research led me to reset the sensor by inserting a paperclip into a hole I hadn’t noticed. After re-pairing the sensor, I was in business! Or was I?! The sensor wasn’t responding, despite recent status updates.

Threading the sensor through the house needle

This led me to the next culprit: the garage is too far away (one floor and the other end of the house) from my Apple TV, which acts as a Matter controller, while the Eve sensor relies on Thread as its communication protocol. What’s a Matter controller?⁴ And what’s Thread?

Matter is an overarching standard, painstakingly developed even as low-power sensing devices and other equipment proliferated in silos. Matter enables Amazon Alexa, Apple Home, Google Home, and Samsung SmartThings devices to communicate across a network, regardless of the network transport medium (Ethernet, Thread, or Wi-Fi). This prevents you from needing ecosystem-specific hubs and lets manufacturers build to a common standard.

Thread fits into this mix as a low-power, wireless networking standard for sensors, allowing them to communicate their status without rapidly draining their batteries, as would happen with Wi-Fi.⁵ Apple initially supported Thread with a proprietary standard, HomeKit-over-Thread, and later added direct Matter support. The Eve sensor was just old enough that it was running on the older standard, but the Eve app allowed me to apply a firmware upgrade. I could then migrate the sensor to Matter, which seems to be more reliable.

Apple made things a little confusing here, too. The 1st-generation Apple TV 4K supports Matter, but lacks a Thread radio, so it can’t work with Thread-based devices. The 2nd generation added that radio, so you can do Matter over Thread. But then, with the 3rd generation, Apple bifurcated Thread hardware support: the 64 GB Wi-Fi only model lacks a Thread radio; you have to spend the now-whopping $249 for a 128 GB Wi-Fi + Ethernet version if you want to use Thread.

Failing an Apple TV 4K with Thread, you can use a Thread border router (TBR), which sometimes comes with sensor kits. This plugs into your network via Wi-Fi or Ethernet and bridges to the Thread network, allowing the Apple TV’s Matter controller to work with the Home app on your devices for automations, notifications, and so forth.

It’s that easy, folks. Sigh.

I do own a 3rd-generation Apple TV 4K with Wi-Fi + Ethernet, because I am a fancy man and a big spender, but I really wanted the reliability of plugging it into my Ethernet network. Yet, I couldn’t get the Eve sensor’s Thread radio to reach across my house to talk to the Apple TV. I bought a TBR, thinking it would solve the problem.

By the time the TBR was delivered, however, the garage door sensor magically connected via Thread to the Apple TV and has been rock solid. The TBR that arrived, on the other hand, I was unable to pair and get working, so back it goes for a refund.

Now my nightly Shortcut works! The only fly in that ointment is that the sensor status reports as Closed or Open in iOS and iPadOS, but as 0 (closed) or 1 (open) in the macOS Home app, in both macOS 26 and the beta of 27. I can live with running the Shortcut from my phone.

[Got a question for the column? You can email glenn@sixcolors.com or use /glenn in our subscriber-only Discord community.]

My beloved sister-in-law-in-law (my wife’s brother’s spouse) texted me with an important problem. Her mother had managed to delete the App Store from her Home Screen. How to restore it? While this is a common problem, I realized that the process is completely unintuitive.

For her mother’s particular situation, the answer felt like a cheat code for a video game: unlock, swipe left (once or more), search, touch and hold, drag. Done.

It’s worth a full review of how modern Home Screen management even works in iOS (and iPadOS), with the App Library view off some people’s radar entirely. Apple has, fortunately, not changed this process so far in the iOS 27/iPadOS 27 betas.

Delete or hide an app

I don’t use the term baroque lightly. However, Apple’s flowchart for choices you can make when deleting an app and what happens next has added some curlicues and ornamentation that can confuse the best of us.

It works like this:

First, touch and hold an app. That’s the easy part.

Now we fork into various swirls and pathways. Choose either Remove App or Require Face ID.

Remove App: You can pick from two options (or tap Cancel):

• Remove from Home Screen: The app’s icon disappears from your Home Screen page. However, it remains in the App Library, which I’ll describe below. More importantly, any data stored on your device remains accessible to the app. It’s like hiding, but not hiding!

• Delete App: Deleting an app removes the app from your device and its data stored on the device. This shouldn’t affect iCloud-synced data if you use the app on other platforms or other identical devices.

Require Face ID: Enabling Require Face ID hides content within the app from Spotlight results. You can add Hide to Require Face ID and also hide the app itself from Spotlight searches. Here are the two Face ID variations:

• Require Face ID: You can’t launch the app without using Face ID, separate from any authentication that may occur within an app for access to its data. You also can’t use data from the app in other apps without Face ID.

• Hide and Require Face ID: One step further, the app icon isn’t actually hidden! It remains in “obscured” fashion on the Home Screen, and appears in Hidden Apps in App Library. A hidden app that produces notifications, handles calls, or sends critical alerts has those suppressed as well. (Despite the statement that “This app will be obscured on your Home Screen,” it was simply removed for me.)

So, let me get this straight. If you remove the app from the Home Screen or Require Face ID, you can still search for it in Spotlight. If you delete it, it’s gone (though Spotlight may show it as a tap-to-download option from the App Store in results). If you Hide and Require Face ID, you can’t search for it or its contents, but you can find it in a Hidden folder in App Library. Got it, got it.

Despite the above, I have to throw in a big HOWEVER.¹ If the app is one of a few made by Apple and preinstalled, you can only remove it from the Home Screen. For instance, touch and hold Settings, Camera, Safari, and a few others, and then choose Remove App: only Remove from Home Screen appears; you can’t delete it, and you can’t use Hide and Require Face ID. Other Apple apps, like Stocks or Weather, may be freely tossed. Perfectly consistent and clear.

Since you now have perfect knowledge of all of these states and interactions, let’s look next at App Library, your Home Screen away from Home Screen.

Apple refused to call it Junk Drawer

I have used a succession of apps that I call, with affection, my “junk-drawer” apps. If you don’t have a drawer in your kitchen that is full of miscellaneous crap that you nonetheless occasionally or regularly need, but which has no place in any other drawer or organizational system, congratulations: you’ve just outed yourself as an extraterrestrial and Earth’s First Contact Committee is on its way.

For example, I throw in every piece of text, PDF, photo of receipt, file, and other detritus that I need to keep handy and email or a folder isn’t accessible enough. Then I can search within the app—convenient since everything is now OCR’d by default, so I can find any word or phrase across all media in the app.²

App Library is the equivalent of this, but just for apps. Do you find Spotlight too effusive in its results? Want to have an organizational scheme for apps you don’t have to set up or maintain? Swipe left until you get to the App Library page. You can scroll through pseudo-folders, from which you can tap to launch apps with full-size icons or tap groups of tiny icons to open the pseudo-folder categorizing those apps. You can also use the search field at the top to search only for apps, as opposed to using Spotlight. At the very bottom of the library is where you find Hidden, the not-exactly hidden set of Hide and Require Face ID apps.

To reverse previous choices from an app, App Library, or via Spotlight if the app is searchable:

• Find the app, touch and hold it, then drag it leftwards onto another Home Page page.
• For a Require Face ID app that’s not hidden, touch and hold it, validate with Face ID, then choose Don’t Require Face ID.
• For a hidden app, tap the Hidden folder, validate with Face ID, then touch and hold the app, and choose Don’t Require Face ID. This removes it from the Hidden folder.

If you deleted an app, you can search for its name in Spotlight, and you may see it in a list with a cloud download icon; you can tap that to restore it, but not its data, which you might be able to recall via logging into an account or it syncing with iCloud. You can also tap Search App Store in Spotlight. Or, launch App Store, search for the app’s name, and tap the cloud download button.

You can’t go Home Screen again

Reader Peter wrote in with a related question I can answer briefly: “No.” I’m sad about that, though. His question? He has a weirdly undeletable app—he can delete it, but it always reappears immediately and persists across migrations and devices. He wondered whether, after he triggered Settings: General: Transfer or Reset Phone: Reset: Reset Home Screen Layout, he could restore his painstakingly set-up Home Screen layouts.

If you have a suggestion, write me, or post in the Six Colors Discord, available to members. Discord is also where you can send a question for the column directly by using /glenn.

We live in a modern, jet-set, hyper-fast world! When we want to buy something online, boom, zoom, we use our fingerprint or face to approve the transaction, so we can grab the next Segway outta here! We don’t have time to enter a credit card! And can we trust a webpage form? Pfeh!

All right, calm down, 1950s inner voice, it’s not that bad. Most of our transactions involving a payment card or other sensitive data can be safely handled over a secure web connection. Apple Pay in Safari is the highest standard, of course, because the payment process involves encrypted elements, and your card number isn’t disclosed to the merchant. The Wallet app in iOS and the Wallet features in iPadOS and macOS further let us automate the entry of numbers and identifiers on pages we trust.

That’s all for automated commerce. What about other scenarios where you need to provide information to someone, often a friend or a local business, in order to transfer money or conduct a transaction? How can you be sure no one else is snooping in?

Make a call

Voice is still one of the most secure means of providing data. The landline wired and cellular wireless networks may be fertile ground for government agencies, but if you need to read a credit-card number or provide a PIN, a call is often the safest way to do so. By voice, you can always have the other person verify details that you believe only they know, or you can verify details to them for the same.

Because we live in a cyberpunk dystopian future, I do have to add a proviso. AI-generated voices have been convincing for a couple of years now—long enough that you shouldn’t trust an incoming call from someone you think you know, and certainly not from a bank, credit-card company, or other financial institution. I mean, I wrote “How To Avoid AI Voice Impersonation and Similar Scams” in January 2024! I assume the state-of-the-art scam is even better.

(The biggest takeaway is analog, too. Set a family password that you demand from a family member who calls asking for money or to do some weird phone or computer set of instructions.¹)

Unless recorded, voice calls also lack persistence, making them impossible to recover later. A real-time Bob needs to be either between Alice and Carol or doing an AI impression of Alice or Carol.

Use secure messaging

I could make the argument that using secure messaging carries even less risk than a voice call if you’ve had an ongoing messaging conversation with someone, so you know it’s really them. Are unsecured text messages being intercepted willy-nilly?² No, but there is also something about sending plain text all over the cellular networks that gives me the willies, nillies aside.

Secure messaging systems include:

• iMessage: While iMessage has seen exploits, they’re government-grade ones. Its secure end-to-end infrastructure is creaky, but unbroken. There’s an extra detail I’ll mention below.
• RCS with encryption: Between Apple Messages on iOS 26.5 or later and an Android device with RCS encryption support, you have a similar level of end-to-end protection. Make sure you see RCS encryption in the text field, or it’s just plain text. You can also use RCS encryption between two capable Android devices—as if!
• Signal: The Signal app and ecosystem have the best end-to-end encryption, as it implements some of the most modern approaches to protecting older messages and current conversations available so far.

The extra note on iMessage is complicated. Briefly, if you use Messages in iCloud, an encryption key to retrieve those messages is included in an iCloud-based iPhone or iPad backup. With access to your Apple Account, someone could potentially retrieve your stored messages. However, if you enable iCloud’s Advanced Data Protection, the backup is encrypted and requires endpoint decryption using one of your devices, protecting the Messages in iCloud encryption key. This should be a worry only if someone manages to obtain your Apple Account, can activate a second factor, and the information you passed via Messages is so sensitive that someone would hunt to uncover it.

Avoid using SMS or MMS text messages (unencrypted plain text), unencrypted RCS (in-transit/at-rest encryption), or other messaging systems where you’re not sure how they handle data protection. WhatsApp can be used if you either have backups disabled or have enabled end-to-end encrypted backups.

Don’t use most collaborative tools

I know that I spend a lot of time in shared documents, whether Google Docs, Notes, Pages, or more esoteric apps or web apps. Most lack the highest level of protection. Shared Pages and Numbers files on iCloud Drive, as well as Google Docs, are encrypted in transit and at rest, and granting shared access is relatively easy (very easy in Google Docs). For iCloud Drive documents, this is true even with Advanced Data Protection enabled.

I’d be dubious about pasting my driver’s license or credit-card information into any of them that are shared with someone else. Ditto, don’t take a picture of your payment card or driver’s license and share it via a Shared Album in Photos, as it has the same issue.

There are two notable (heh) exceptions: if you and the other party or parties to a shared Notes entry or an iCloud Shared Photo Library all have Advanced Data Protection enabled, end-to-end encryption is used.

Consider the risk

As with all decisions around privacy, consider how at risk you and your data are, including voice as data. In most cases, ensuring a baseline level of encryption can be enough. Even when the app or server can “see” your unscrambled information, the transport between your device and the server and another person’s device is encrypted. Someone would have to break into the server to sniff data. If stored on the server, the baseline state would be encrypted at rest; however, the server operator would manage those encryption keys.

For peace of mind, if not strictly necessary, I’d encourage you to consider using end-to-end encryption when you can. It’s so easily available. For someone to crack your connection, they would need to obtain one of your devices and be able to unlock it. Otherwise, the path between you and someone else is effectively impregnable.

For further reading

I cover message security extensively in my book Take Control of FaceTime and Messages, which I recently updated to include the beta release of RCS encryption for Apple-to-Android communication.

For more on Wallet, I wrote an entire book on that seemingly simple app and set of features, Take Control of Apple Wallet. The book arose from the frustrations of finding where things in Wallet (and outside Wallet but related to it) lived.

On the security side of things, Take Control of Securing Your Apple Devices includes detailed advice on the ins and outs of physical security: how to ensure someone with access to your hardware can’t reach your data.

[Got a question for the column? You can email glenn@sixcolors.com or use /glenn in our subscriber-only Discord community.]

Years ago, in the era between the introduction of the iPhone and the modern period of widespread cellular coverage, my wife and I were driving with our quite young children across the vast, unexplored expanse of north-central Pennsylvania, en route to a family wedding. We had plotted out the route and knew where we were going: Eagles Mere, a tiny, former luxury resort town once at the end of a railway line. The town used to attract well-known actors, as well as New York City denizens, who would escape the summer heat and polio outbreaks back in the city.

As we tootled along, chatting with the kids and keeping them occupied, we suddenly went off the grid. We were still on a state highway, not yet turned to a smaller road, and yet there was no coverage. We figuratively slapped ourselves in the head. Had we gotten AAA maps or printed out whatever the technology was of the day—did MapQuest even still exist? No. We relied on having continuous cellular service. Readers, we did not wind up in the forest for a week, discovered by rescuers clad in bark and branches, feeding the children non-toxic berries. But we did learn a lesson.

Always have a map that doesn’t require cellular access! I mean, duh, of course, but we had been lulled in our coastal urban elitism to expect service, service, everywhere!

Of course, it wasn’t long after that Google introduced a download option; Apple added one for its Maps app a full decade later.¹ Downloading a map lets you access nearly everything you need while off the cellular grid, in an area where you don’t have service, when you have just a trickle of data, or when data access is metered and high-cost.

The usual provisos apply: something could go wrong, you might not have access to your iPhone or iPad, the map might be missing details you need, and so on. If you want a belt to go with your suspenders, consider printing out a paper map! Yes, paper still exists.

Common offline features

In both Google and Apple’s mapping apps—say that five times fast—a Download button should appear whenever you search by a name, like a park, business, or city. Otherwise, you have to hunt a bit, as I’ll explain below. Downloadable maps may require from about 150 MB to over 1 GB of storage, depending on the area you select and the amount of detail Apple or Google downloads for that selection.

The settings for both apps are quite similar: tap your profile picture in either app, then tap Offline Maps; in Google Maps, tap the gear icon. Now you can change preferences:

• Downloads (Apple)/Download preferences (Google): Opt whether to download only over Wi-Fi or over both Wi-Fi and cellular.
• Automatic Updates (Apple)/Auto-update offline maps (Google): When enabled, maps are periodically refreshed.
• Optimize Storage (Apple): The app automatically purges maps you haven’t used “in a while.”
• Sync with Apple Watch (iPhone only): You can also push offline maps to your Apple Watch, which has a lot less storage, but, really, how much are you keeping on it, anyway?
• Only Use Offline Maps (Apple): This forces the use of offline maps even when you have an Internet connection, which is useful when you are in one of the bandwidth scenarios above: low throughput or expensive usage-based service. Google automatically switches to an offline map when there’s low throughput available, or you have no connection.

Download from Apple Maps

If you search for a city name and there’s an exact best result, a Download button appears in the search result. I’ve also found that if Maps isn’t certain the match is correct, you may have to tap the city link, and then a Download button will appear. Enter a business name, tap the link that corresponds to the firm you want, and you can then tap the more (…) icon and choose Download Map. This also works for street addresses.

In all of the above cases, Maps shows you a portrait selection by default on an iPhone and a landscape one on an iPad. Adjust the area shape, and pinch and expand to zoom in or out, then tap Download. The estimated map download size appears above the Cancel and Download buttons.

Manage your offline data by tapping your profile picture and tapping Offline Maps. You’ll see all the stored maps, can delete them, and control settings. Tap a map, and you can then tap Rename, change the included area, or tap Delete Map. In the main Offline Maps view, tap Download New Map (iOS/iPadOS 26) or Add Offline Map (iOS/iPadOS 27) to search for a location and then immediately have the area-selection view appear.

Download from Google Maps

Search for a city name and tap a result. You may have to swipe left in the button bar to see the “Download offline map” link; tap it. If you’re viewing a map, tap your profile picture, then tap “Offline maps.” Tap “Select your own map,” then zoom in or out on the current map area; tap Download when you have the selection you want.

From your profile picture, tap “Offline maps” to view the list of available maps. Tap a map and tap Delete or Update, or tap the Edit (pencil) icon to rename it. From the main view, you can also tap the More (…) button to the right of a map to update, rename, or delete. You can’t change the selected area, however.

Print a goldarned map out

Having a physical map may seem like something from the early 2000s, so long ago few living souls remember it, but it’s an extra backup against calamity. With a color inkjet printer, you can squeeze a fair amount of detail into a letter-sized or A4 page.

Printing directions via Apple Maps in macOS Tahoe worked surprisingly well. It was like the good old days, but better, offering multiple pages of maps and step-by-step directions. You just get a standard print dialog, with no details to tweak. Google Maps on maps.google.com has a print mode, but it’s lackluster, with no step-by-step directions. In Safari, the preview and printed output were incorrect.

Postscript: Where she’s going, there are no Offline Maps

Of course, right after I wrote this, my older went off on a hike and came back…complaining about the poor performance of Offline Maps in Apple Maps. She was in a not-terribly-remote area in the mountains, about 90 minutes away, with intermittent cellular access. She had downloaded the map before she left, thinking it was successful. But even with no cell access or with the Offline Maps forced-use option enabled, she couldn’t get the offline map to work. Fortunately, the trail was well-signed and full of people, and there was no real chance of getting lost.

Back in Seattle, examining Offline Maps, these out-of-area maps she downloaded showed up as 0 KB. We tried to download the map again, but Apple Maps wouldn’t let us use the trailhead as a landmark. We found a nearby place and tried to download. The progress circle showed that a download was first underway, then complete, yet the download was again 0 KB. This happened repeatedly. More bizarrely, the offline map couldn’t be deleted. I attempted to replicate on my iPhone, where everything worked without error, including using the trailhead as the place name—a Download button appeared as expected.

We didn’t test Google Maps for comparison, since her hike was over, but it’s another reason to download and check that your offline maps are up to date and valid before departing.

[Got a question for the column? You can email glenn@sixcolors.com or use /glenn in our subscriber-only Discord community.]

I have a Mac Studio M2 Max with 32 GB of RAM and a 1 TB SSD in front of me. While not the most powerful personal computer you can purchase today, it is among the most computationally capable ever made—a vastly capable machine. So why do I have to wait for typing to catch up with me and see a rainbow spinner on the regular?

I’ll tell you why: iCloud Drive and Spotlight. Apple lacks any transparency about how iCloud Drive works or fails. The same is true of Spotlight. These big black boxes churn away, performing a million billion operations a day, and we don’t know exactly what they do. That’s not me being conspiratorial: I honestly don’t care what’s happening under the hood—until it breaks. Without diagnostic tools, even someone like me, ostensibly an expert, can be completely at a loss and waste many hours.

I wrote “Cloudy with a Chance of Insanity: Unsticking iCloud Drive” for TidBITS back in October 2023 about a multi-month odyssey with Apple technical support in trying to dislodge unsyncable files.¹ That problem has barely surfaced since—an 80K file will sometimes get stuck for a while—and I thought Apple might have really solved syncing, at least as exhibited on my Mac. I receive dramatically fewer emails about iCloud Drive than I used to, which is another data point.

But Mr. Edge Case here can always find a way to break something.² I’ve been working on a large manuscript for my upcoming book, Flong Time, No See, a revised and expanded collection of researched articles I’ve written about printing and type history over the last several years.³ I pasted in text that was typically copied from Web pages, and wound up with over 250 footnotes.

While putting together the files for this book, Apple released its Creator Studio system, and shipped Pages 15. After having no problems, I dutifully switched over. This was months ago, and as I continued to work on this reasonably large file—weighing it at about 60,000 words now—everything seemed fine.

A few weeks ago, however, I started to experience system slowdowns. Pages was taking up 12 GB of system memory! System load went through the roof! CPU consumption was outlandish! All signs pointed to corespotlightd, a long-time enemy of performance. That daemon handles background indexing for Spotlight, and the slightest thing wrong in a file or directory, or perhaps due to mild corruption in its underlying files, turns it into a rampaging beast that eats processor cycles like I consume potato chips.⁴

There’s a well-known procedure for killing this beast, though another is spawned from its remains: stop the index, delete the index files, restart, and re-enable indexing. From the Terminal, use these commands. Make a backup before proceeding. Take extreme care with rm -rf, as a misstep in entering or copying can wipe out files!

 sudo mdutil -a -i off
 rm -rf ~/Library/Metadata/CoreSpotlight

You can use Restart from the Apple Menu while holding down the Option key (to avoid being asked), or you can take a shortcut from Terminal, assuming you have ensured all files are saved:

 sudo reboot

After your Mac restarts, go back to the Terminal and re-enable indexing:

 sudo mdutil -a -i on

For many (perhaps most) people, this solves the problem. For me, it just delayed it. With some isolation using System Settings: Spotlight: Search Privacy, I added specific folders, such as mail archives, since that seemed like it might be part of the problem.

One piece of advice I found suggested that if I thought Pages was the problem, I should exclude the iCloud Drive path containing Pages files. Fine! I clicked the plus icon in Search Privacy, pressed Command-Shift-G to bring up the path dialog, entered ~/Library/Mobile Documents/com~apple~Pages/, and clicked Choose. This seemed to work for a while, then nothing availed.

Finally, after analyzing logs and caches, the culprit was clear. It was not that large a Pages file: every time I saved, Spotlight’s worker bee was performing excessive re-indexing that consumed gigabytes and one or more processor cores. Moving the file to a local directory (in my Documents folder) while editing eliminated the problem. It also freed up space, as the temporary Spotlight indexes and Time Machine snapshots had become absurdly large.

What could Apple have done to help here? This is where I would hope machine learning, coupled with some interactive code- and system-expertise bots, could help:

• Note that a system component is acting well outside known parameters.
• Identify CPU usage that is tied to Apple-owned processes.
• Provide a troubleshooting tool, even suggesting it in notifications.
• Create human-readable logs that don’t require system administrator knowledge to interpret.

In the case I describe above, an Apple-created daemon was rampaging out of control due to a single identifiable file!—cascading into other problems. It should be solvable by Apple. The fact that we have more power under the hood by orders of magnitude in the past, coupled with neural cores in the CPU packages, just makes this even more embarrassing. Solve Siri, Apple, yes, but real transparency and troubleshooting in macOS would also make a big difference.

[Got a question for the column? You can email glenn@sixcolors.com or use /glenn in our subscriber-only Discord community.]

Apple’s built-in screen sharing support for Mac-to-Mac connections has always been a help for those of us with remote setups: headless Macs acting as servers, an office and home Mac, or the laziness of having Macs in different parts of your house you want to access without standing up.¹

Under the hood, Apple relies on VNC (Virtual Network Computing), a fairly ancient standard at this point in time, and you probably get the sense of its creaking joints if you use the Screen Sharing app regularly.² But it’s possible you didn’t know that, starting in Sonoma, Apple added a “super excellent” mode to Screen Sharing as an option when you connect two Macs with M-series chips. Called High Performance, it can deliver on its name.

Let’s shift into overdrive

When you connect to another Mac using Screen Sharing, you’re given a choice of which mode to use. Let’s walk through the connection steps:

1. Either launch the Screen Sharing app and double-click the Mac’s name in a list, or, in the Finder, Control-click/right-click the Mac’s name and choose Screen Sharing. (There are still more ways to start, too.)
2. From the Select Screen Sharing Type options, you can select Standard, which is VNC-based, or High Performance, which adds Apple’s secret sauce on top.
3. Click Continue.
4. Enter your credentials.
5. The screen appears, and you may need to enter your macOS account password on the remote Mac to unlock it.

In that pathway, if you choose High Performance, you’re presented with different options. You can also click the info (i) button to the right of an existing connection in the Connections window in Screen Sharing, and choose High Performance from the Screen Sharing Type pop-up menu to save that option for the next connection.

With a Standard connection, you get a pixel-for-pixel remote view of the other Mac’s display or displays. It’s just like you’re sitting in front of it. In fact, if you use the same account as the currently logged-in user, the remote Mac shows what you’re doing to anyone who looks at it. (You can log in as another user, and a session starts in the background that doesn’t appear on the remote display screen.)

High Performance takes a different approach. You can opt to create one or two virtual displays on the remote Mac, each with independent resolution, high-dynamic-range (HDR) support, and other features. It’s like being a remote user of the computer rather than sharing. (This mode doesn’t change the remote display resolution or other settings.)

With a High Performance connection between Apple silicon Macs, you gain these advantages:

• You can choose one or two virtual displays, regardless of the number of displays connected to the shared computer.
• The Dynamic Resolution option lets you resize a virtual display to the native resolution of your local screen, up to 4K (3840×2160 pixels) or, with HiDPI, up to 1920×1080. You can click the Dynamic button on the Screen Sharing toolbar or choose View: Dynamic Resolution during a live session.
• Stereo audio passes over the connection, as does improved video. The connection supports HDR (for richer low-light and shadow tones), 4:4:4 chroma subsampling (uncompressed color data for improved fidelity), and high frame rates of 30 or 60 frames per second (for more stable video streaming, such as when watching a video or using video-editing software).

The downside of High Performance is that it imposes severe requirements for it to work well. You need 75 Mbps per 4K display and low network latency, which requires fast Wi-Fi with a gigabit-or-faster mesh or wired backbone if there are multiple network routers or base stations. However, that requirement also means that when you’re using High Performance, it feels very much like sitting in front of the other display rather than viewing it remotely.

If you want the depth of HDR Video, you have to enable it on the remote Mac via System Settings: Displays. The option for HDR Video appears in a Preset pop-up menu, but, of course, only if the display supports the right HDR signal. HDR can be enabled or disabled from the View menu and Screen Sharing toolbar, if it’s available.

Because the remote display is blacked out when using High Performance (even when connecting as the currently logged-in user), this can be seen as a privacy advantage if you have concerns about anyone else viewing the remote Mac’s screen. However, High Performance mode’s utility really lies in treating Screen Sharing like a high-speed display tunnel instead of a jerky remote view.

For further reading

If you’re looking for more detailed information about High Performance mode or any aspect of Mac-based file and screen sharing, you might consult my book, Take Control of Apple Screen and File Sharing.

[Got a question for the column? You can email glenn@sixcolors.com or use /glenn in our subscriber-only Discord community.]