Portfolio Optimizer vs Razorpay IFSC

Portfolio Optimizer is a free, no-signup Web API implementing modern-portfolio-theory algorithms — mean-variance and minimum-variance optimization, risk and performance analytics, backtesting, and factor-model tools — over JSON, so it can be called from Python, Excel, Google Sheets, or any HTTP client without an SDK. The homepage explicitly advertises free access with no registration required, and a live test against a real optimization endpoint (api.portfoliooptimizer.io) returned `Access-Control-Allow-Origin: *` on both a route-not-found and a malformed-payload response, confirming CORS is enabled; the same responses carry a `WWW-Authenticate: Key` header hinting at an optional key for higher throughput, though the observed default rate limit is a modest 1 request/second.

Razorpay's IFSC Toolkit is a free, keyless lookup over India's Indian Financial System Code directory, compiled from RBI and NPCI public data, returning the bank, branch, address, and supported payment rails (NEFT/RTGS/IMPS/UPI) for any given code. The underlying dataset and API server are open-sourced on GitHub, with official client libraries for Node, PHP, Ruby, and Go.