A web-based decision engine that ingests your mortgage details (rate, balance, term, prepayment penalties), competing debts, investment accounts, tax bracket, and risk profile, then runs side-by-side scenarios showing projected net worth, monthly cashflow, and break-even points for each strategy. The tool generates a personalized recommendation with clear reasoning and stress-tests outcomes against market downturns, job loss, and interest rate changes. Includes specialized modules for refinancing, moving with existing mortgages, Smith Manoeuvre strategies, and lump-sum windfalls.

Elevated mortgage rates (6-8%) combined with strong equity markets have made the pay-down-vs-invest question more financially consequential than it has been in 15 years, while AI now makes personalized financial modeling cheap to deliver at scale.