WhatsApp also gracefully handles being offline and queuing messages for later.

That can’t be said of iMessage.

Offline queueing is a fantastic feature! I know someone who lives in a remote area whose phone only gets network connectivity when they walk up a specific hill. In many ways, they use WhatsApp the way most people used email in the dialup days: read and compose offline, then go online once a day to send and receive new messages.

Edit: I sometimes get a chuckle when they say "Look at this cool picture I took", and then receive the picture some days later when the conversation thread has moved on. I guess they'd have stayed in thr coverage area for long enough for the entire image to upload.

This is so bizarre to me. How can a native application not implement that, while a third-party application nails it!?

I know when people are in low signal as I get a green then exactly the same blue some time later.

Which creates issues when you have signal but don’t have a sub to send that actual message over sms.

Sometimes sms failover creates further problems because when travelling you’re more likely to have intermittent wifi than intermittent sms access.

I think luckily you can turn off auto sms fallback - but it does indeed default to on.

Because Whatsapp is huge in Africa IIRC

It's huge in many countries where Internet service has been expensive or difficult to come by. Case in point, all my relatives in Eastern Europe use WhatsApp, and with better bandwidth options, some are using FB Messenger for video calls,.as well.

Facebook used to have (has?) 2G Tuesdays, where devs had to test their stuff at 2G speeds, for this exact reason.

Everyone I know in Belgium/The Netherlands/... uses Whatsapp. It's even got into the language: "to app someone", i.e. "iemand appen".

Any idea how it compares to Signal? They should be essentially using the same protocol. I also used it with good results with slow connectivity, but never tried on bad 2G...

Unfortunately I don't have any data points on how Signal operates 2G speeds

I have tried to use signal in a location that had voice, but no data (a very old, very rural tower in the middle of nowhere) a few years ago, and signal was completely worthless. Even though it can read and receive SMS, it seems to require a data connection to send..

Yes, everything except voice and SMS requires data

Yes, that would be the case for any OTT messenger (so, anything but SMS).

The encryption protocol is fairly unrelated to how an app handles poor connectivity. It’s a bit like comparing different websites handling poor connectivity differently even though they are all served over HTTP.

I believe their communication layers are fairly different – WhatsApp used to use something based on XMPP at least until a while ago; I'm not sure what Signal uses, but I vaguely remember it being based on HTTP?

Can definitely be, I never investigated in detail, although I used alternative open source clients for both (signal-cli and a long time ago yowsup), so the information should be in there...

I hoped that Signal's use of HTTP was as a fallback in case a direct connection could not be established to use a more "compact" protocol, but I possibly don't remember correctly what I've read...

Telegram also has pretty amazing support for poor connectivity environents

> For all the faults of Meta, WhatsApp seems to be the only company that cares about people with bandwidth measured in kbps, sometimes fractions thereof.

WhatsApp was built with low-bandwidth/high-latency/high-packet-loss in mind well before Meta acquired them.

I suppose we can give them vague amounts of credit for not making those use cases worse since the acquisition.

They have made it worse...

It used to work just fine on 1kbps.

Now it is pretty much unusable over dialup or GPRS.

To be fair, it used to be "encrypted" using a scheme not too far removed from ROT13; now it's using the Signal protocol, which probably requires quite a few more bytes per message.

For example, messaging a contact with multiple devices connected means that your phone has to encrypt your message to each of their clients independently.