F1 to K1 visa?
Answer:
1. Its OK to get married on F1. Its not OK to do it very soon.
Example. 3 month from entry - too soon. 1 year is fine. It shouldnt look like you had marriage in mind before applying for F1. So if its too soon, just postpone marriage (its Ok, F1 visas are usually long).
2. K1 is not the way, its for fiancee outside US, K3 is for spouse outside US,. You actually will not apply for visa, but rather for adjustment of status. Its forms I-485. (also other forms in addition).
F1 forever
uscs.gov
I-130 / I-485 at www.uscis.gov
So go ahead and get married. If you go for the fiance visa, you will have to leave the country and will not be allowed back till you receive your visa. That can take up to a year. Since you are already here, and even better here legally, you should have no problem with the marriage. After you got married you should file to change your status from non-immigrant, which is your current F1 visa, to immigrant. In a couple of month you and your spouse will have an interview with INS and if they find your marriage legitimate you will receive a 2-year conditional green card. Before the 2 years is up you have to file for removal of the condition. The condition being you have to stay married for that time and hopefully after that too. :)
Somebody mentioned that you should get married rather later than sooner after you came here with F1. It is not necessarily so. What matters is what was your intent when you entered the country. If you entered with F1 and knew you are going to get married that is fraud. If you decided to get married while you were already here, you done nothing wrong. Besides, intent is almost impossible to prove.
For details see the INS's official website or call them.
www.uscis.gov
The immigration information post by website user , MyTend.com not guarantee correctness