Alpha Vantage alternatives
10 other financial data listed here. Alpha Vantage is freemium.
CoinGecko API
Crypto prices and market data
EOD Historical Data
Historical and live market data for global exchanges
Financial Modeling Prep
Prices, statements and ratios through a REST API
Finnhub
Real-time quotes, fundamentals and news
FRED API
Economic time series from the St. Louis Fed
Massive (formerly Polygon.io)
Market data APIs for stocks, options and crypto
OpenBB
Open-source investment research platform
SEC EDGAR
US public company filings database
Twelve Data
Market data for stocks, forex, ETFs and crypto
yfinance
Python library for Yahoo Finance data