Can anyone help identify the sex of these chicks?

[kymeads]

I have 4 chicks about 4 weeks old each. I want to know what gender they are so that we know before hand if they are rooster or not. If anyone can help, thanks! Ive uploaded some pics.

 

[Rhodebar Lover]

1/2-pullets
3/4-cockerels

 

[kymeads]

1/2-pullets
3/4-cockerels

Thank you!

 

[HappyClucker7]

3 and 4 are 100% cockerels. 1 and 2 look like pullets for now, but 4 weeks is still kind of early to tell for certain, so I would post again in about 2 weeks just to make sure.