I'm Czech so I could help, although you did not mention the name. Anyway, here are some sites I use for this purpose. They allow you to search surnames ("příjmení" in czech), and will show you how common it is, apart from other things. You need to be careful about diacritics though.

• https://www.prijmeni.cz/ - In the following example you can see there are 1511 occurences of Koláček (833th most common surname, every 6797th person has it). Plus you also see there are similar surnames "Kolaček" and "Kolacek".

• https://www.kdejsme.cz/ - result for the same example as above

Of course over time layou can change, though I think it should be much of a problem using automatic translation.

I'm Czech so I could help, although you did not mention the name. Anyway, here are some sites I use for this purpose. They allow you to search surnames ("příjmení" in czech), and will show you how common it is, apart from other things. You need to be careful about diacritics though.

• https://www.prijmeni.cz/ - In the following example you can see there are 1511 occurences of Koláček (833th most common surname, every 6797th person has it). Plus you also see there are similar surnames "Kolaček" and "Kolacek".

• https://www.kdejsme.cz/ - result for the same example as above

There are others but these should work. Of course over time the layout can change, but I don't think it should be much of a problem using automatic translation.