You might be thinking that, if you wanted to find out how good your 4G signal was, you could just get your phone out and start using it. How wrong you are. You need to use a map. That way, you can see if your phone is a piece of crap, or indeed, find out what the reception is like a place you're about to visit, so if it is lousy, you can take a load of books and ignore everyone that way.
Good thing Ofcom have come up with an interactive map, where you can check out the phone reception, 3G and 4G connections all over the UK.
There's four mobile phone providers included in the map - Vodafone, O2, EE and Three. One good thing is that you can use the tool to see which company has the best service in your area, which could help if you're planning on getting a new phone contract.
Basically, all you have to do is pop in a postcode into the search bar and then hit one of the options from 'voice calls', '3G data' or '4G data'. And boom! You're away.
You can also check indoor and outdoor coverage too. If you're wondering where Virgin is, they use EE's network. And if you're wondering where TalkTalk are, they use Vodafone's.