Prosper will pre-qualify you for a loan and tell you what tier your credit score qualifies for (AA - D?). The interest rate on the loan is based on your credit tier. And it also displays on the funding page for investors to see. My scores when I got the Prosper loan were in the mid to upper 600's and at that time they qualified me as Tier AA. I don't know exactly what their tiers are but I believe on their site you can put in your info and they will give you a rate based on a soft pull. Of course there is a hard pull if you decide to actually apply.
Starting Score: 500's