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.
Where these values come from
CORS is verified by us — we read the Access-Control-Allow-Origin header from a real response (last checked 2026-07-31). Free tier and restrictions marked verified were read from the provider's own pricing page on the date shown, and that page is linked so you can re-check it yourself. Rows marked not verified are ones we could not confirm at the source, so we do not publish a number for them. Pricing and licence terms change without notice — confirm with the provider before you commit. If you spot a value that is out of date, tell us and we will correct it.
Discontinued
One API in this table no longer responds: FreeForexAPI. Their terms are kept for reference, but you cannot sign up for them.
| API | Free Tier | Rate Limit | Commercial | Attribution | Auth | CORS | Caching | Notable Restrictions |
|---|---|---|---|---|---|---|---|---|
| Marketstack | 100 calls/month, end-of-day data verified 2026-08-01 | 100 calls/month (free) | ✕ | Req | API Key (query parameter) | Yes | Yes | Free plan: end-of-day data only with 1 year of history; no intraday data |
| Alpha Vantage | 25 calls/day verified 2026-08-01 | 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 verified 2026-08-01 | 100 calls/day (free) | ✓ | No | API Key (query parameter) | Yes | Yes | Free tier limited to US stocks and delayed data |
| FreeForexAPI Discontinued | Unlimited (fair use) | Reasonable use expected | ✓ | No | None | Yes | Yes | Limited currency pairs; no historical data |
Attribution Details
Last updated: 2026-04