iPhone 4 Browsing Internet/FaceBook etc over 3G very slow

i would suggest check with your network provider, before assuming its a faulty device.

i would call O2 and explain the problem to them, they may be able to diagnose the issue, it may be that your account is not set up correctly for the iPhone Data or something.

did you not get the phone through O2 then?

well if there was nothing O2 could do, then maybe you do have a faulty unit.

personally though i would wait 24 hours and keep checking it, you never know, there may be something in your area that happens to be interfering with the signal at the moment, if you have the ability, maybe you should try what you suggested earlier, of trying a different sim/phone on the same network and if possible different networks, that way you may be able to determine if this is true before replacing it and finding out you're getting the same problem.

good luck

Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_2_1 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8C148 Safari/6533.18.5)

Change your cellular data apn to these:

APN: mobile.o2.co.uk
Username: bypass
Password: leave it the same (password).

this is assuming your o2 Uk an pay monthly... Their idata apn is awful slow, I can get up to 5.5mb/s on the above settings and it's noticeably faster. O2 won't tell you about this tho!

Ps, yes this apn is covered by your free data as it's an official o2 access point, it's just not the iPhone specific one

Would it be possible to get some numbers? Download the Speed Test app or something?

This is very hard to diagnose without any data to go off of.

Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_2_1 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8C148 Safari/6533.18.5)

Swc, o2 by default put all their mobile data thru their proxy server which has a big effect on speed, the details I give above simply bypass this proxy giving you direct access and much quicker speeds

THANK YOU MyRomeo

Thank you MyRomeo, your advice has worked a charm. Whoopieeeeeeeee! I've been struggling with 3G ever since getting my iPhone 4 (which by the way I absolutely LOVE to bits) but due to not being able to use my phone from work I never really needed 3G as I always connected to the Internet via my home wi-fi.

Anyway enough of my waffle, for those like myself who didn't know where to change of APN settings on the iPhone 4 here's the route:

From the main screen of your iPhone tap Settings > General > Network

Tap Mobile Data Network

For Pay & Go customers.
Tap APN and change idata.o2.co.uk and enter payandgo.o2.co.uk (Please note that "o2" needs to be written with a letter "o" and not a zero)

For Pay Monthly customers.
Tap APN and change idata.o2.co.uk and enter mobile.o2.co.uk (Please note that "o2" needs to be written with a letter "o" and not a zero)

You don't need to change your username and password

If you're not using an iPhone ignore the Visual Voicemail APN box - it's not available to Pay & Go customers or Pay Monthly customers (with a non iPhone tariff)

Under MMS

For Pay & Go customers.
Tap APN and change idata.o2.co.uk and enter payandgo.o2.co.uk (Please note that o2 needs to be written with a letter o and not a zero)

For Pay Monthly customers.
Tap APN and change idata.o2.co.uk and enter wap.o2.co.uk (Please note that o2 needs to be written with a letter o and not a zero)

You don't need to change your username and password

Turn your iPhone off and on again

These are the iPhone 4 iOS 4.2.1 updated settings