Pick iMessage if everyone you talk to uses an iPhone or another Apple device and you want messaging that works out of the box. Pick Signal if your contacts are spread across iPhone, Android and desktop, and you want encryption that doesn't depend on carriers or device type. Mixed group chats are where the gap between the two shows most.
This is a choice most iPhone owners never think about until a friend asks them to install another messenger, or a group chat with Android users turns green. Both apps encrypt conversations and both are easy to start. The difference sits in who's on the other end and how their messages travel.
The green bubble problem
According to Apple's support article, texts from an iPhone to a phone from another maker travel as RCS or SMS/MMS, and the RCS ones appear in green. It then adds a condition: RCS can only be end-to-end encrypted when every participant's carrier offers that protection.
So the same app can give you a protected chat with one friend and something weaker with another, depending on their carrier. You often won't think about it in the moment, and the bubble colour is the only clue you get.
Signal works differently. It credits its own open source protocol for the end-to-end encryption, and that covers every message sent through it. The trade-off is that the other person has to install it too.
Who runs each service
Encryption protects what's inside a message. It doesn't settle who runs the service that carries it. iMessage is Apple's own, built into its devices. Signal is published by a 501c3 nonprofit, and the protocol behind its encryption is open source, so the code is there for anyone to inspect.
For some people that difference is the whole decision. If you like being able to point to open source code or a nonprofit publisher, that leans one way. If you trust the company that made your phone and want everything in one place, the built-in app makes life simpler.
When iMessage is all you need
- Families and friend groups where everyone already uses an iPhone, iPad or Mac.
- People who like delivery and read receipts and typing indicators without setting anything up.
- Anyone who doesn't want to ask contacts to download another app.
Between Apple devices, these chats travel over Wi-Fi or mobile data and Apple says they're encrypted end to end. For an all-Apple circle, that covers a lot of ground with zero effort.
When the extra install earns its place
- Anyone whose regular contacts include Android users.
- Groups that mix phones and want the same protection for every member.
- People who want a desktop app on Windows or Linux as well as a Mac.
- Anyone who'd rather their messenger be run by a nonprofit.
One practical point on computers: you can't start on a laptop. Signal's download page lists desktop apps for Mac, Windows and Linux, but they need the app installed on your phone first, and then you link the computer to it. If you swap phones often, keep that phone handy whenever you add a new computer.
Feature by feature
| iMessage | Signal | |
|---|---|---|
| Publisher | Apple | 501c3 nonprofit |
| Built in | Yes | Download |
| Chatting with non-Apple phones | Goes as RCS or SMS/MMS | Both sides install it |
| Encryption | End-to-end, per Apple | Open source protocol |
| Desktop apps | Not stated | Mac, Windows, Linux |
| Phone needed first for desktop | Not stated | Yes |
| Receipts and typing indicators | Yes | Not stated |
Three questions that settle it for most people
- How many of the people you message most don't use an Apple device? If none, iMessage covers you. If several, the carrier condition on RCS applies to every one of those chats.
- Do you need to message from a Windows or Linux computer? The desktop row in the table above answers that one.
- Does it matter to you who publishes the app? The publisher row in the table settles it.
Common ground
More than you might expect. Both encrypt conversations end to end when both people use the same app. Both are quick to start. For a one-to-one chat between two iPhone owners, either will do the job well, and the choice comes down to habit.
If you're also weighing a third option, compare iMessage vs WhatsApp and Signal vs WhatsApp before you decide.
Group chats are where it gets awkward
One-to-one chats are easy to sort out. Groups are harder, because a single Android phone changes how the whole conversation behaves on Apple's side. If you run a family group, a sports team chat or a work channel with mixed phones, that's the conversation to move first if privacy matters to you.
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Moving a group takes a little diplomacy. Ask one person who uses Android and one who uses an iPhone to try the new group with you for a week before inviting everyone else. If they're happy, the rest usually follow. If someone can't or won't install a new app, keep them in the loop by another route rather than leaving them behind.
Until then, ask one question before you share anything private in a mixed group, such as an address or travel plans: would you be comfortable if this travelled without end-to-end encryption? Apple's carrier condition means you can't rule that out from your side of the chat.
Before you switch, check these
- List the ten people you message most and note who uses which phone.
- Ask your most important group chats whether everyone would install a new app.
- Install the new app on your phone before any desktop device.
- Start one group in the new app and keep the old one running for a fortnight.
- Review the new app's notification settings so important messages don't go quiet.
- Check each app's help pages on moving old conversation history, and keep the old app installed until you're sure you have what you need.
Plenty of people end up using both, one for family on iPhones and one for everyone else. There's nothing wrong with that, as long as you know which conversations are protected and which aren't.
If you're helping an older relative make the change, set the new app up on their phone yourself, add the three or four people they talk to most, and send them a first message so the chat is waiting for them. A familiar face in the contact list does more than any explanation.
Frequently asked questions
Does a nonprofit publisher guarantee privacy?
No publisher is a guarantee on its own. Judge each app by what it says about encryption, and read its privacy policy before you decide.
Should I warn people before I switch?
Yes. Post a short note in your busiest chats saying where to find you, so nobody keeps writing to an app you've stopped checking.
Does Signal have an iPad app?
Its download page lists desktop apps for Mac, Windows and Linux, each linked to a phone. Check that page for tablet support before you plan around one.
Does iMessage work on a Mac as well as an iPhone?
Apple describes it as sending to another iPhone or Apple device, so a Mac can join in. Check Apple's support pages for the steps to set it up there.
Do read receipts work in both?
Apple lists delivery and read receipts plus typing indicators for its app. Signal's pages don't list them, so check its settings.
