It’s almost always better to pay off any unsubsidized student loans that have the highest interest rates. So if you have both types of student loans, you will want to focus on repaying the unsubsidized loans first. Then, you can start chipping away at the subsidized loans with higher interest rates.
Subsidized loans with the lowest interest rates will generally make you spend less, so these should be left to the end. By paying off your unsubsidized loans first, you will find yourself enjoying more financial freedom as you work to eliminate your debt.