A quick and dirty look at iMessage data usage.

[dffdce]

I was curious at least to get an order of magnitude when it comes to data used by iMessage. So I fired up tshark and watched the "wire" while sending an iMessage to friend. The message itself consisted of "Test" as the subject and the body was "Test message".

Bottom line:
1,042 bytes were sent
498 bytes were received.

These were actual bytes on the "wire" so EVERYTHING is included. The whole sequence is via https from my iPhone 4 on WiFi and 17.149.36.84 which by the way resolves to nk11p01st-courier014-bz.push.apple.com.

Note that the reason I'm calling this test quick and dirty is that it was the third or fourth iMessage that I sent within about 5 minutes. I believe that some of the normal Certificate / key exchange / Handshaking was done on the first message and cached. I didn't see any of that "stuff" during subsequent messages.

 

[VideoNewbie]

I was curious at least to get an order of magnitude when it comes to data used by iMessage. So I fired up tshark and watched the "wire" while sending an iMessage to friend. The message itself consisted of "Test" as the subject and the body was "Test message".

Bottom line:
1,042 bytes were sent
498 bytes were received.

These were actual bytes on the "wire" so EVERYTHING is included. The whole sequence is via https from my iPhone 4 on WiFi and 17.149.36.84 which by the way resolves to nk11p01st-courier014-bz.push.apple.com.

Note that the reason I'm calling this test quick and dirty is that it was the third or fourth iMessage that I sent within about 5 minutes. I believe that some of the normal Certificate / key exchange / Handshaking was done on the first message and cached. I didn't see any of that "stuff" during subsequent messages.

can someone simplify what this guy is trying to say?

 

[Nokaoi]

????

WTF did I just read?

 

[Yumunum]

Yeah I totally know what you're talking about...

Ah, who am I kidding. Please explain?

 

[fins831]

i think it was like 1 kb, which means your have to send 1024 to send 1 megabyte worth of data, and 1024 megabytes to hit 1 gig of data, so iMessages (non MMS) only messages cannot exceed the 2GB limit unless you send more than the debt of the United States...

sending MMS is another story entirely...

Also, just remembered that you download the message and its half the size, obviously compressed to save data, so 1kb per sent msg and .5 per received, still a ton of data to be used in order to reach cap.

 

[Thetonyk123]

i think it was like 1 kb, which means your have to send 1024 to send 1 megabyte worth of data, and 1024 megabytes to hit 1 gig of data, so iMessages (non MMS) only messages cannot exceed the 2GB limit unless you send more than the debt of the United States...

sending MMS is another story entirely...

Also, just remembered that you download the message and its half the size, obviously compressed to save data, so 1kb per sent msg and .5 per received, still a ton of data to be used in order to reach cap.

Ok Thanks I get it a little bit better now

 

[r2shyyou]

i think it was like 1 kb, which means your have to send 1024 to send 1 megabyte worth of data, and 1024 megabytes to hit 1 gig of data, so iMessages (non MMS) only messages cannot exceed the 2GB limit unless you send more than the debt of the United States...

sending MMS is another story entirely...

Also, just remembered that you download the message and its half the size, obviously compressed to save data, so 1kb per sent msg and .5 per received, still a ton of data to be used in order to reach cap.

Very interesting. I wonder what the stats are for MMSs. It would obviously depend on content but I wonder if the same "full sent/half received" applies.

 

[Gemütlichkeit]

can someone simplify what this guy is trying to say?

WTF did I just read?

Yeah I totally know what you're talking about...

Ah, who am I kidding. Please explain?

Cliffsnotes: you send 1k of data for a typical iMessage which is next to nothing in the grand scheme of things.

Thanks thread starter for this info. Can you measure the data sent when it's a picture next?

 

[fins831]

I have an unlimited texting plan, but a limited data plan. Will using iMessage with my friends charge on my data plan? And if it does, is there a way to disable it so it is back to regular texting?

Yes iMessage will eat at your data, albeit not that much, unless you send pictures and videos.

Go into settings, go to messages, and turn off iMessage, and then your on text only, and won't eat any extra data.

 

[shardey]

Yes iMessage will eat at your data, albeit not that much, unless you send pictures and videos.

Go into settings, go to messages, and turn off iMessage, and then your on text only, and won't eat any extra data.

Being on wifi helps take the load off of the 3g data.

 

[pcunite]

Basically iMessges are so tiny as to work fine with a 200mb data plan. The downside is that the iPhone does not automatically disable cellular data when a user customizable threshold gets reached. This leaves us all vulnerable to getting a $1,000 bill one day because we sent a few pictures of the kids to grandma and we weren't on wifi for some reason.

 

[gemnilocs]

can someone simplify what this guy is trying to say?

lmao! I was thinking the same thing! it was like the Charlie Brown and the Peanuts... wom wom wom.....

 

[mroddjob]

Bottom line:
1,042 bytes were sent
498 bytes were received.

Is that 498 bytes received when sending the iMessage rather than when receiving a message? In which case it would be the total of the 2 used when sending an iMessage.
Can you get your friend to send exactly the same message to you and see how much data is used to receive a message.

 

[DouchGod]

Basically iMessage uses a insignificant amount of data when only transmitting text.

 

[garybUK]

I was curious at least to get an order of magnitude when it comes to data used by iMessage. So I fired up tshark and watched the "wire" while sending an iMessage to friend. The message itself consisted of "Test" as the subject and the body was "Test message".

Bottom line:
1,042 bytes were sent
498 bytes were received.

These were actual bytes on the "wire" so EVERYTHING is included. The whole sequence is via https from my iPhone 4 on WiFi and 17.149.36.84 which by the way resolves to nk11p01st-courier014-bz.push.apple.com.

Note that the reason I'm calling this test quick and dirty is that it was the third or fourth iMessage that I sent within about 5 minutes. I believe that some of the normal Certificate / key exchange / Handshaking was done on the first message and cached. I didn't see any of that "stuff" during subsequent messages.

How did you capture the data? did you disable cellular and send over WIFI using a packet sniffer and packet analyser?

 

[r2shyyou]

I have the same thinking. any one can do it?

Did you read the posts below the one you quoted, where the OP's post was simplified?

 

[dffdce]

Sorry for the geek speak.

This all started at a brief lunch time conversation where the premise was basically that iMessage just shifted the cost from text messages to your data plan. Made me curious so I had to investigate.

As several people have pointed out even if you're a mega-texter say 5,000 texts per month, and if those were all iMessages it would only use 7.7 MB of your data plan. So if you're trying to squeak by on a 200 MB/mo plan (like I am) you'd still have 192.3 MB left after 5,000 iMessages.

To answer some of the other questions.

The numbers (1042 sent and 498 received) I quoted in the first post DID include delivery notification.

When that same message (Subject: Test Body: Test message) was sent to me my phone received 745 bytes and sent 185 bytes.

The data was captured by turning "Cellular Data" Off so that WiFi would be used. And then the data was captured real time with tshark (command line version of wireshark) and then analyzed with wireshark the (graphical version).

Finally the last thing I want to try is an MMS. Hopefully will get a chance today or tomorrow.

 

[jman240]

Very nice. I was debating this with a friend the other day.

If anyone still doesn't understand this he used a nifty little utility that monitors your network traffic to see how much data an iMessage used.

Result: very very very little.

That's good news for anyone on a limited data plan and great news for people wanting to kill their texting plans.

Since he used bytes you have the initial message using 1024 bytes or roughly 1kB (kilo-byte) and each subsequent message using much less than that. A megabyte is one million bytes or 1000 kilobytes. Worst case scenario you can send 1000 iMessage messages per megabyte. If you're on the 2gb plan that's 1,000,000 iMessages a month. I don't even think that's possible for a teenager nowadays.