Many Universities have Pre-application forms (Electronic or by email). You can submit details like GPA; Courses completed, GRE, TOEFL Scores, Research interest, a brief introduction about yourself, etc. It provides useful information about your profile to the admission committee. There are no fees for pre-application, and official transcripts and letters of recommendation are not required. If admission committee like your profile they will encourage you to apply officially! Many Universities recommend international students to apply for pre-application forms. We highly recommend and encourage to go through this route (for international applicants). It will save you some application cost and you will know where you stand. Again you will not receive official offer for admission but you will be encouraged to apply (if university likes your profile). There is no guarantee that you will receive official admission offer.
Pre-Application Forms for some Programs:
When you send information during pre-application you need to be serious and treat it as official application (even if you think you have a strong profile for that college).
Note: Not all colleges offer pre-application evaluation. Some colleges will not respond if you try to contact them about your profile/credentials. Each department receives thousands of applications and it's really not possible to evaluate each application (maybe at some point it will be done using artificial Intelligence!).