Best 4G UK deals

With Three up and running in London, and even Giffgaff set to offer 4G in the next few weeks, 4G has hit the mainstream in the UK. Most new smartphones are 4G-capable, so if you're shopping for a new contract, which networks have the best deals? Let's have a look.

Value for money

I'm going to look only at SIM-only deals here, because it's almost always cheaper over the course of a contract to buy your phone upfront and get a SIM than it is to get a free or subsidised mobile from a network or phone shop.

All these deals include unlimited calls and texts, unless otherwise noted.

Vodafone only offers 4G on 12-month, SIM-only contracts. They start at £21 for 1GB, £26 for 3GB, £31 for 5GB and £41 for 9GB. The more data, the less you pay per GB, but it's unlikely you'll need more than 5GB. The 5GB and 9GB deals also include free Spotify or Sky Sports Mobile for the length of the contract.

O2's SIM-only deals are called Simplicity. (Its Airtime deals are a little cheaper, but you have to get your phone from O2.) These start at 1GB of data for £16, going up to £19 on 28 March, then it's 2GB for £21, 5GB for £25, and 8GB for £30.

EE's deals begin with £16 per month for a pathetic 500MB. A more useful 1GB will set you back £21, 3GB is £26, 5GB is £31, 8GB is £41, and 20GB is a whopping £61. Those are all 12-month contracts, but 30-day deals are available for two or three pounds more at each level.

Three, the UK's smallest proper network, is the only one to offer unlimited data. Eat all the 1s and 0s you like, plus 600 minutes and 5,000 texts, for £15.90 per month for a year, or get the same deal for a single month with 200 minutes for a mere £12.90. Bump up to 2,000 minutes for £20 per month for a year, or £23 for one month. Other SIM-free deals only offer 500MB or 1GB of data, but start from £6.90.

Giffgaff, which piggybacks on O2, will launch 4G services in April. It'll max out at 2GB, with £10 per month getting you 2GB and 250 minutes, and £15 netting you 2GB and 500 minutes.

Tesco also uses O2's network, and adds data on the top of its normal contracts if you want to make the most of 4G. The more expensive your contract, the less the extra data costs. Picking its middling £10 per month contract with 1GB included, you can add 1GB for £2.50 extra, 3GB for £7.50, or 7GB for £12.50, among other options.

Coverage

Each network has a coverage checker, in which you should put your home and work postcodes, or anywhere else you might want to use ultrafast mobile broadband. EE is by far the best, followed by Vodafone and O2, which cover the big cities and most populous areas of Britain. (Giffgaff and Tesco share O2's coverage, of course.) Three is miles behind, currently covering only London and a few other cities reliably.

Speed

Vodafone, O2 and Three don't say exactly how fast their 4G networks are. O2 points to Ofcom's 4G explainer, which says 3G averages 1Mbps, and 4G should average 6Mbps -- a massive bump, if not quite home broadband speed.

A quick test here in central London just clocked 39Mbps download and 14.7Mbps upload on Three, and we've seen similar scores for Vodafone and O2, although not consistently.

EE has an offer called "Double Speed", which is less widely available than its normal 4G service, but promises 24-30Mbps, compared with its own measurement of 12-15Mbps for its normal 4G areas. It's an extra £3 per month.

Extras

EE carries on the Orange Wednesday tradition of 2-for-1 cinema tickets and has its own film rental store, which doesn't count toward your data allowance.

O2 has a bewildering array of offers, ticket discounts and all sorts -- read more here.

Vodafone has the best 4G perks by far. Shell out £31 for 5GB (or more) and you'll get 12 months of free Spotify music streaming or 12 months of free Sky Sports Mobile. Spotify is worth £10 per month, but Sky is worth a fiver, because you only get Sky Sports 1 and 2.

So which is the best UK network for 4G?

If you live outside a big city, your only real choice right now is EE. Its 5GB deal for £31 per month is probably the best value for most people, but you may need less data than that.

If you live in London, give Three a try. It's by far the cheapest, and the only unlimited offer around. I think when it rolls out across the country, if it can maintain the kind of speeds we've seen in the capital, Three will be the automatic choice.

Meanwhile, Tesco's 3GB for £17.50 (with 1,000 minutes, not unlimited) is excellent value and should work well in most big towns and cities -- check the coverage though.

If you're data-hungry and already pay for Spotify, Vodafone's 5GB for £31 is terrific value too because it's effectively £21 per month. Don't bother with Sky, as that's half the value -- get a cheaper deal elsewhere and pay for it separately.