Finance APIs Terms Comparison
Side-by-side comparison of free tiers, rate limits, and usage restrictions for 4 finance apis.
Terms of service may change. Always verify with the official API documentation before building production applications.
| API | Free Tier | Rate Limit | Commercial | Attribution | Auth | CORS | Caching | Notable Restrictions |
|---|---|---|---|---|---|---|---|---|
| Marketstack | 100 calls/month, end-of-day data | 100 calls/month (free) | ✕ | Req | API Key (query parameter) | Yes | Yes | Free plan: HTTP only, end-of-day data only, no intraday |
| Alpha Vantage | 25 calls/day | 25 calls/day, 5 calls/min (free) | ✓ | Req | API Key (query parameter) | Yes | Yes | Free tier rate limit is very strict (5/min); premium required for real-time |
| StockData | 100 calls/day | 100 calls/day (free) | ✓ | No | API Key (query parameter) | Yes | Yes | Free tier limited to US stocks and delayed data |
| FreeForexAPI | Unlimited (fair use) | Reasonable use expected | ✓ | No | None | Yes | Yes | Limited currency pairs; no historical data |
Attribution Details
Marketstack: Marketstack attribution required on free tier
Alpha Vantage: Must credit Alpha Vantage as data provider
Last updated: 2026-04