driftcurve vs SquirrelPlan

driftcurve is an open-source household retirement planning engine for projecting finances and comparing retirement outcomes. It can model multiple household members, account types, debts, mortgages, pensions, Social Security and property sales. Its default Monte Carlo simulations resample annual market data from 1966–2024 across equities, Treasuries, residential real estate, inflation and Bitcoin. Users can adjust historical returns toward their own long-run targets or enter static annual assumptions. Risk-based spending guardrails solve for monthly spending and suggest adjustments based on portfolio thresholds and probability of success. A Compare page puts two scenarios on one chart. In default local mode, household data and saved scenarios stay in browser localStorage, while forecasts run through a Python backend; there is no account or server-side database persistence. Optional multi-user mode adds email/password accounts, server-side sessions, and stored profiles and scenarios. The project offers forecast and guardrails API endpoints, plus authentication, profile and scenario endpoints in multi-user mode. It is free under Apache License 2.0. The maker describes it as an educational modeling tool, not licensed financial, investment, tax or legal advice.

SquirrelPlan is a free, open-source tool for projecting and visualizing a financial future. Enter assets, liabilities, monthly income and expenses, then add assumptions for returns, interest or annual increases. You can direct surplus savings among asset classes and set different strategies for different life periods. Retirement inputs include current and legal retirement ages, estimated net monthly pension, and optional early retirement age and withdrawal rate. A standard simulation projects from those figures; an optional Monte Carlo run produces hundreds of projections using randomized annual asset returns. Charts and a table show wealth over time, while scenario analysis supports comparisons between assumptions. Preset plans cover Recent Graduate, Early Career, Mid Career and Late Career. SquirrelPlan is a client-side web application, also runnable by opening its static index.html file in a modern browser without installing dependencies. Plans are stored in browser local storage; the project has no backend server. Data can be imported or exported as JSON, and the README lists multi-language support. The free plan is free.