Why your phone buzzed first

You send “on my way” to the family group. Your sister's phone lights up straight away. Your brother's lights up ten seconds later. Your dad's doesn't light up for twenty minutes.

Nothing went wrong. That message took a different road to each phone, and some roads have more waiting on them than others. To see why, it helps to follow one message the whole way, slowly, one step at a time.

The journey of one message

A message never flies straight from your phone to your friend's. Phones don't know where other phones are. It always goes through a few computers in between, and each one has a job.

So there are really two deliveries. The message itself goes from your phone to WhatsApp's computers and on to your sister's phone. The notification, the little banner, is a separate tap on the shoulder that WhatsApp asks Apple or Google to deliver, because only they can wake a phone whose app is closed.

While you wait for a reply: I also make a daily word game. Play today’s Long Story Short, one true story cut down to five of its own words. About two minutes.

Every other delay on this page comes from one of those steps: making the copies, the line Apple and Google keep open to every phone, a phone that is switched off, or a phone that is asleep.

Who makes the copies

A message to five people has to turn into five messages at some point. Some apps make the copies on your phone. Others send one copy and let their computers make the rest. It depends on how they lock the message so that only the right people can read it.

iMessage makes every copy on your phone. Apple's security guide says each message “is individually encrypted for each of the receiver's devices”. If your friend has an iPhone, an iPad and a Mac, your phone makes three copies just for her, and sends them one after another.

WhatsApp groups send one copy. WhatsApp's whitepaper says “the sender transmits the single ciphertext message to the server, which does server-side fan-out to all group participants”. Signal and Messenger groups work the same way. But a one-to-one WhatsApp chat flips back: since 2021 your phone “encrypts and transmits it N number of times to N number of different devices”.

Discord works like a teacher reading out a register. One process runs each server and goes down the list of everyone connected. In big servers Discord found about 90% of members weren't looking at the server at all, so it stopped sending them anything until they open it.

So on iMessage, somebody's copy always leaves your phone first. That alone can put a second or two between two people in the same group.

When your phone is off

If your phone is switched off, or in a tunnel, or out of battery, nobody can deliver anything to it. So where does your message go? It waits, on someone else's computer, in a kind of waiting room. Each kind of message has its own waiting room, and each one has a different rule about how long it will wait for you.

Apple says iMessages “are queued for delivery to offline devices” and “stored on Apple servers for up to 30 days”. WhatsApp keeps an undelivered message “in encrypted form on our servers for up to 30 days as we try to deliver it. If a message is still undelivered after 30 days, we delete it.” Once a message is delivered, both delete it from their servers.

The notifications have a waiting room of their own, and it's much smaller. Google holds them for up to four weeks. Apple holds them too, but only one per app: “If multiple notifications are sent while the device is offline, each new notification causes the prior notification to be discarded.” That's why a phone coming back on doesn't show fifty WhatsApp banners. It gets one tap on the shoulder, and the app then fetches every waiting message itself.

Old-fashioned text messages wait at your mobile network. The network keeps trying for a set time, usually between one and three days, and after that the text is simply dropped. Email works differently again: it doesn't wait at all, it's kept. Your email provider stores it until you delete it.

The line every phone keeps open

Your phone doesn't keep asking every app whether anything new has arrived. That would flatten the battery by lunchtime. Instead it keeps one connection open to Apple or to Google, and every app's notifications travel down it. Apple calls it “a persistent network connection to the push service that will be shared by all push-capable apps on the system”.

The weak spot is that a quiet connection looks dead to the equipment in between, like your Wi-Fi router, which drops it to save memory. So the phone sends a small heartbeat every so often to say it's still there. In 2014 Android sent one every 28 minutes on mobile data and every 15 minutes on Wi-Fi, but many home routers give up on a quiet connection after five to ten minutes. A study of more than 100 mobile networks found eleven that cut them in under ten.

If the line is cut and the phone hasn't noticed, a notification has nowhere to go. It waits at Google until the next heartbeat fails and the phone reconnects. Press play to watch an hour of it.

That's your dad. His phone isn't slow. His notification was waiting for a heartbeat.

When your phone is asleep

A phone lying still on a table with the screen off is asleep, and phones sleep deeply to save battery. On Android this is called Doze. Apps lose the internet, and the phone only wakes for short windows now and then, further apart the longer it lies there. Google's documentation says normal messages are “delivered immediately when the device is not sleeping”, but during Doze “delivery may be delayed to conserve battery”. Only high priority messages can wake it.

iPhones handle it on the sender's side. Every notification sent to Apple carries a priority: 10 means “send the push message immediately”, 5 means “at a time that takes into account power considerations for the device”. And since iOS 15, each notification also says how urgent it is, which decides whether it lights up the screen at all.

Some Android makers add their own battery savers on top of Google's, and close apps in the background without asking. The developers behind Don't Kill My App rank brands by how badly they do it:

Worst first, from dontkillmyapp.com, October 2026, ranked by developers' experience rather than lab tests. Pixel, Nexus and Android One phones run Google's own Android and sit apart from the list.

Now put it together

Here's the family group again: five phones, each doing something slightly different. Change what any phone is doing, then send, and each one tells you which step held its message up.

The people are made up. The delays are typical values from the measurements below.

How long it really takes

Hardly anyone times delivery to real phones, because it means keeping phones on a shelf and watching them. The login company LoginTC does exactly that, and published its averages.

At the University at Buffalo, researchers sent notifications to a group of Android phones and timed every arrival. Within ten seconds, nearly 80% of phones that were online had it, but only about 40% of phones that had been offline. For most messages to most people the whole trip takes a second or two. The long waits live at the edges: a cut line, a sleeping phone, a phone that was off.

If you’d rather spend those two seconds on something else, play today’s Long Story Short.

Email takes a different road

Email doesn't start with a tap on the shoulder. It travels from the sender's mail computer to your mail computer, which keeps it until your app collects it. We can show this part with real numbers, because we send a newsletter, and Amazon, which delivers it for us, logs every step.

In June we sent one issue to 6,523 people. They didn't get it at the same moment. Our script goes down the list at about two emails a second, so the last person's copy left 56 minutes after the first. Who gets the newsletter first? Whoever happens to be near the top of the list.

When an email arrives at a provider's door, the provider has to accept it before it can go anywhere near your phone. Some were much quicker than others.

Gmail took three quarters of a second. Apple's iCloud Mail took 4.6 seconds, six times longer. And one Gmail address took a lot longer than that.

A mail computer that's unsure about a sender, or simply busy, can say “try again later”, and the sending computer waits and tries again. Some do it on purpose to every new sender, betting that real senders come back and spam machines don't.

Nobody reads that fast. Those were almost certainly security robots, which open every link and picture in incoming mail to check it before a person sees it.

So why did your phone buzz first?

Probably because your app was open and hers was closed, or your phone was awake and hers was asleep, or her router had quietly cut her line and her phone hadn't noticed yet. If you were both on iMessage, your copy may simply have left the sender's phone first. And if her phone was off, your message is sitting in a waiting room, and it will keep for 30 days.

Almost every one of those delays is there on purpose, because a phone that lasts until bedtime was judged to be worth more than a message that arrives a few seconds sooner.

It goes out at about two a second, so somebody always gets it first. · More from The Data Drop · Long Story Short