Safari not working on wifi but all other apps are working like Facebook Twitter etc. IPhone 5s. Used to work perfectly 2 days ago.

I use an iPhone 5s and since the past 2 days safari has stopped working on my wifi. I have full network, wifi bars are not grey and all my other apps seem to work like twitter, Facebook, whatsapp etc. However YouTube doesn't seem to work either. I haven't made any changes to my wifi or phone software in the past 2 days. And I have tried resetting my router, resetting the phone and resetting network settings and yet the problem prevails. What do you suggest I do ? Safari gives an error saying server not responding/cannot be found something like that.