Thanks guys, I did this with bitaddress as well I just forgot it, my main issue is with some apps showing ads when in use, so I turn off internet and when switch between open tabs, if I'm offline the page of btckeygen  refreshes by itself and nothing works, until I go online again. I'm using this because I can quickly find different bits, determine bit ranges fast without counting the chars, lol.

It's also useful to just enter anything as private key and hit visualize, it doesn't ask for 64 char key, before using this site, I had to add 63 zeros just to get the public key/ address of key 0x1 for example.

Other than educational use, I have no other use of this tool.
Thank you very much.