Moor Frog

Thanks for the help Márton.

It's moor frog, Rana arvalis. Common frog males and agile frog males also getting a little bit darker at the breeding season, but not as blue as moor frog males.

Thanks a lot. They are found in the same place so I will try to see if I can classify them.

You're welcome. These 3 frogs are very hard to tell apart on pictures. You have to rely mainly on habitat and distribution, and this is changing. Ideally you need to have a close look at their hind legs. The shape of the snout and the position of the eardrum are also helpful.
Here's a good amphibian site:
http://www.amphibiaweb.org/
For Europe I also recommend the Collins guide to Reptiles and Amphibians of you have a special interest there.

Thanks for the help, yea I'm not good at classification of amphibians as well.

Hi Faredin! It could be temporaria or arvalis, and I see you also have dalmatina in Copenhagen. Diffilcult for me to get closer :-)