We pay extra on our house payment and the particular bank where mortgage is automatically applies any extra to the principle. Not all lending agencies have that policy for their loans and mortgages. When I was paying on my student loans I always paid extra on it and it reduced the amount of time a good bit.
If you haven’t done so yet, you might want to consider getting the required payment lower, so the impact of your money is greater. I use the Income based repayment plan (IBR) for my student loan. You may not qualify for that one but there are other options. My goal was to make sure that the extra payments I’m making went towards principal, not interest. That might shave time off your anticipated payoff date. Hope that makes sense. Ignore if you’ve already done this.