CGM Data Sharing While Traveling: The Connectivity Playbook (2026)

Your continuous glucose monitor, or CGM, only shows its numbers on your phone. Remote sharing is what puts them on someone else's phone: Dexcom calls it Share on your side and Follow on theirs, with you as the sharer and them as a follower. Abbott's version is called LibreLinkUp, and the follower's data view is linked to Abbott's LibreView account system. For anyone traveling with type 1 diabetes (T1D), this is the remote safety net: a partner at home, a parent of a kid at camp, a friend who promised to keep an eye on things.

But sharing is not magic. It has one hard requirement that travel loves to break: an internet connection on both phones. Your sensor talks to your phone over Bluetooth, a short-range wireless link between devices. Your phone then sends your numbers to your followers over the internet. If either link goes quiet, your followers stop seeing you, and you usually will not get a warning about it. With Thanksgiving and December holiday trips about to put millions of phones into airplane mode and onto foreign networks, this is the season to get the connectivity piece right.

The two moments sharing stops

Dexcom's official travel guidance names the first one plainly: your data will not transfer to followers while your phone is in flight mode, and the company says to make sure your followers know you are on a flight. Airplane mode cuts the internet link, so readings still appear on your phone (more on the Bluetooth trick below) but nothing reaches the cloud, and nothing reaches your followers.

The second moment is sneakier: both the sharer's and the follower's smart devices must have a mobile data connection or Wi-Fi. That is Dexcom's exact requirement for Follow. It means sharing can also die on your follower's end, at home, if their phone is offline, or on your end if you land in another country with no roaming data and no Wi-Fi nearby. Abbott's rule is the same shape: both the Libre wearer and the follower need a network connection for LibreLinkUp readings to flow. Before a trip, tell your followers the plan, including the hours you will be offline, so a blank screen at home reads as "they are flying" instead of "something is wrong."

The flight-day fix: airplane mode, then Bluetooth back on

Here is Dexcom's official flight-day procedure for smartphone users: switch your phone to airplane mode, then manually turn Bluetooth back on to keep receiving sensor data. Airplane mode shuts off your cellular and Wi-Fi radios; turning Bluetooth back on restores only the short-range sensor-to-phone link. Your own readings keep flowing to your phone. Sharing to followers stays paused until the internet link returns.

Three official add-ons for flight day:

• Receiver users keep the receiver powered on during the flight. The receiver is Dexcom's dedicated handheld display; it keeps working on its own Bluetooth link to the sensor without any internet.
• Always follow airline crew instructions and check your airline's device policies. Dexcom's guidance is general; the crew's word on board is final.
• After landing, turn your cellular data back on and open the G7 app. Once your phone has internet again, sharing resumes to your followers, who may have been staring at a frozen number for hours. A quick "landed, back online" text keeps everyone calm.

Keep the internet side alive: decide before you leave

The airplane-mode trick protects the Bluetooth half. The internet half needs a plan too, especially on international trips where your phone can land with no data at all. There are three common ways travelers keep a phone online abroad, and none of them is diabetes-specific: your carrier's own roaming plan, a local SIM card bought at the destination, or a travel eSIM (an electronic SIM, a digital version of a SIM card you download to your phone instead of inserting). What matters for CGM sharing is not which option you pick; it is that your phone and at least one follower's phone both have internet at the same time. Roaming plans can surprise you with bills, local SIMs take setup time at the airport, and eSIMs need a phone that supports them. Pick one before departure day, test it at home, and do not leave this to the arrivals hall.

Two honest caveats. First, hotel and airport Wi-Fi are real internet, but they are also the least reliable option: captive logins expire, speeds vary, and your phone may drop off overnight. If sharing continuity matters to you, treat hotel Wi-Fi as a bonus, not the plan. Second, even with a solid plan, brief dropouts happen. They do not mean your devices are broken. When the internet returns, new readings start flowing again.

The before-you-leave app checklist (from Dexcom)

Connectivity is not the only thing that can break sharing abroad. Dexcom's travel page lists a small but strict checklist for using their apps in another country:

1. Update to the newest version of the product app before you travel.
2. Log in to your account on the app before leaving your home country.
3. Know your username and password and keep a note of them somewhere you can reach.
4. Understand the consequence: if you skip the above, you cannot reinstall the app while abroad if something goes wrong.

If issues come up on the road, Dexcom's guidance is to call your home country's technical support before uninstalling or reinstalling anything, because most issues can be resolved without reinstalling the app. That advice pairs with our own G7 international post: Dexcom apps have country-specific store listings, and deleting the app abroad can strand you.

Related reading: Dexcom G7 International Travel: App Region Locks (2026) covers which app versions work where and what to do if yours is the wrong country's app.

The new Follow app: cross-regional syncing

Here is the good news from Dexcom's latest update cycle. The newest Dexcom Follow app includes cross-regional syncing, so a sharer and their followers can connect across country lines. In plain terms: you can be in Spain and your follower can be in Ohio, and the sharing link still works, as long as both phones have internet. This is a real change from the older behavior where regional app stores could silently break the sharer-to-follower link abroad.

But the update is a two-sided deal. Dexcom says previous versions of the Follow app will no longer be updated, so the upgrade instructions say to download the new Dexcom Follow app from the Apple App Store or Google Play, and both sides need it. When your follower logs into the new app with the same email address their invitation was sent to, their existing sharer connection is auto-imported and data populates within about a minute. Practical advice: get every follower to update the app at least a week before the trip, and confirm you can see their connection as active. Do not discover a stale app version from a hotel room.

LibreLinkUp on the road

If you use a FreeStyle Libre sensor, the same internet rule applies. Abbott's LibreLinkUp lets you invite up to 20 family members, friends, or caregivers to remotely view your readings and receive notifications and glucose alarms when alarms are enabled. Sharing requires registration with LibreView, and both your phone and your follower's phone must have a network connection for readings to flow. Everything in the connectivity sections above, the both-phones-online rule, the pre-trip plan, the offline flight hours, applies here too.

When the backup becomes the plan

Sharing is a safety net, not a treatment tool. For your own treatment decisions on the road, pack your fingerstick blood glucose meter where you can reach it, and bring 20% more supplies than the trip should need (our house rule). Dexcom's own guidance for checkpoints says to use a blood glucose meter for treatment decisions whenever your phone or display device is out of your hands, and the same logic applies whenever your app is unavailable. For lows, our own routine is sugar packets: one packet at 60 to 70 mg/dL, two below 60. And remember that followers cannot act on what they cannot see: the severe-low plan still belongs in a written form someone has, not only in a follower's app. Our companion post has that plan in detail.

Related reading: Traveling Solo with Type 1 Diabetes: The Safety Playbook (2026) (the severe-low plan when nobody is beside you), Charging Your Diabetes Devices on the Road (keep the sharing phone alive), and Omnipod 5 + Dexcom G7 Travel Guide.

The connectivity checklist

1. Text your followers your flight times: sharing pauses in flight mode.
2. On the plane: airplane mode on, then manually turn Bluetooth back on.
3. Receiver users: keep the receiver powered on during the flight.
4. Confirm both your phone and each follower's phone have mobile data or Wi-Fi.
5. Choose your abroad-internet plan (carrier roaming, local SIM, or travel eSIM) before departure day.
6. Update the Dexcom product app to the newest version while still at home.
7. Log in to the app and confirm you know your username and password before leaving.
8. Have every follower update to the latest Dexcom Follow app and confirm the link is active.
9. Pack a fingerstick meter where you can reach it, plus sugar packets for lows.
10. If something breaks abroad: do not uninstall; call your home-country Dexcom technical support first.

FAQ

Does Dexcom Share work when my phone is in airplane mode?

Your own readings keep coming if you turn Bluetooth back on after enabling airplane mode, which is Dexcom's official procedure. But sharing to your followers stops: Dexcom states that data will not transfer to followers while you are in flight mode. Tell your followers you are flying so a frozen number does not alarm them.

Why did my followers stop seeing my data on a trip?

The usual suspects, in order: your phone lost its internet connection (roaming not set up, hotel Wi-Fi dropped, airplane mode left on), your follower's phone lost its internet connection, or one side is on an outdated app. Dexcom requires both devices to have mobile data or Wi-Fi, and the new Follow app needs to be on both phones for cross-country syncing to work. Check connectivity on both ends before assuming a device is broken.

Does Dexcom Follow work across countries?

Yes, with the latest Follow app: Dexcom's update notes say it includes cross-regional syncing so a sharer and followers can connect across country lines. Both sides need the updated app, and both need internet. This is separate from the app store region-lock question covered in our G7 international travel post.

Does LibreLinkUp work while traveling?

Yes, as long as the internet rule holds: both the wearer's phone and the follower's phone need a network connection, and sharing requires LibreView registration. You can invite up to 20 followers, and alarms they have enabled keep working over the connection.

Can I fix sharing problems by deleting and reinstalling the app while abroad?

Not safely. Dexcom says you cannot reinstall the app while abroad unless you updated it and logged in before leaving your home country, and their guidance is to contact your home country's technical support before uninstalling or reinstalling anything. Most issues resolve without a reinstall.

Is hotel Wi-Fi enough to keep sharing alive?

It can carry sharing, but it is the least reliable option: logins expire and phones drop off overnight. For a trip where sharing continuity matters, have a real data plan (carrier roaming, local SIM, or travel eSIM) and treat hotel Wi-Fi as backup, not the primary link.

Additional details

What this post covers: why CGM data sharing (Dexcom Share/Follow, LibreLinkUp) stops during flights and on poor internet; the official airplane-mode-plus-Bluetooth procedure; the both-phones-online rule; the pre-trip app update and login checklist; the new Follow app's cross-regional syncing; and the flight-day connectivity checklist.

Last verified: October 22, 2026, against Dexcom's official travel FAQ and Follow app update FAQ, and Abbott's LibreLinkUp product and support pages.