P/L Charts
OptionStrat
A trader toolkit for visualizing payoff charts and quickly exploring different option structures and scenarios.
Backtesting
Option Omega
A very strong backtesting platform for SPX, QQQ, and more, including intraday-style analysis and even 0DTE-based testing.
Calculation
Options Profit Calculator
Useful for building a concrete options strategy from real options data and checking profit, loss, and break-even directly.
Research
Barchart Options
Broad options coverage with chains, unusual activity, and additional filters for daily research.