By now you may have seen how-old.net, a new Microsoft site which tries to guess a person's age based on a photo.
As BuzzFeed has already established, it's pretty bad at guessing the age of celebrities. And Disney princes.
But are you any better? Try guessing the age of these UK politicians.
It might feel like he's been around for a lot longer, but Cameron isn't even 50 yet.
He might look like he's just left university, but Ed is firmly in his mid-40s.
Clegg might not be able to join a coalition government after the election, but at least he's not turned 50 yet.
In fairness to the app, it was pretty accurate on this one.
The app unfairly added a whole 10 years to the Scottish first minister's actual age.
The app's guess of 34 was a *bit* out.
The Labour candidate for Streatham is young. But he's not *that* young.
BoJo is 50!
The mayor of London might be a bit older than he looks, but he's not 59.
That means he can celebrate many more Ed Balls Days to come.
Patrick Smith is a senior reporter for BuzzFeed News and is based in London.
Contact Patrick Smith at email@example.com.
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