I seem to have run down my phones data plan quite a lot this month compared to normal. I was wondering if this was because I used it for tethering (obviously I know that tethering uses data too, but the amount of tethering I used doesn't seem to match the amount of data that I'm missing from my contract). So I was wondering, does tethering use more data than if I use the Internet on the phone itself rather than tethering it to another device?
Provided that the same thing is being accessed on both the phone and the tethered device, then the data usage will be the same. i.e. if a picture if 50kb, then it will always take 50kb to download regardless of what you use to download it. However when you access a website on a phone it is pretty common for it to be in 'mobile format', which means that they've removed a bunch of the extra images and content of a page that aren't necessary. This can reduce the size quite a lot depending on the how the website is configured. For example, the mobile version of the Wikipedia front page (en.m.wikipedia.org) is 14.3kb. The normal version (en.wikipedia.org) is 143kb - ten times as large. For YouTube, they are 26kb and 733kb respectively. If you accessed these websites on your phone they'd come in mobile format, but if you did it on a laptop that was tethered to your phone, then they'd come in the larger, normal format.
