driftcurve vs Fidelity Planning & Guidance Center

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.

Fidelity Planning & Guidance Center is a free web tool for reviewing retirement readiness, investment strategies, and possible next steps. Retirement Analysis lets users explore hypothetical scenarios based on current savings and estimated future contributions, while multiple independent financial goals can be created and monitored. The analysis uses historical returns, market volatility, and correlations to estimate potential retirement income. Fidelity says Probability of Success replaced the Fidelity Retirement Score as a holistic measure of financial plan strength and supports planning beyond retirement. Information may carry into other Fidelity tools, including Guided Portfolio Summary and Fidelity Income Strategy Evaluator. The tool may use financial details previously provided to Fidelity, a workplace plan sponsor, or a third party, so users should check them for accuracy. Its projections are hypothetical, do not represent actual investment results, and are not guarantees. The analysis is informational and nondiscretionary, not personalized advice. Generating a plan has no fee, though investment expenses and account transaction fees may still apply.