I’m currently 19, and i’ll be 20 years old by the end of next year. I’m a future undergrad international student. It’s hard to get into U.S schools as international student in the first place, but does it look bad If i’m older. I did really poorly in HS, but re did the courses online, and did really well. Just wondering if anyone can help me this.
Nope.
You really don’t fit the description of an “older” student. Don’t worry about it.
Thanks 
Do U.S Universities look down on online courses in any way? I personally found them more challenging, but i have no idea what U.S uni admissions think of them.
.
You will likely not get credit for them but it shows you have the drive to improve over your high school studies.
What do you mean by “credit”?
If you’re willing to pay tuition and fees, you’ll find a school that accepts you. Being 19 or 20 and starting college isn’t a hindrance at all. Your spotty academic record will be your problem. It may require you to really search far and wide to find a college willing to accept you. Have you taken TOEFL, ACT or SAT? That will help.
“Is It Harder to Get Into Colleges if You’re Older?”
It doesn’t speak well for online courses.