Fulusly API vs National Bank of Poland API

Two free Currency Exchange APIs compared on access, reliability and developer ratings, using data from our daily health checks.

The verdict

Choose Fulusly API if its data fits your use case better; on access and reliability it's level with National Bank of Poland API.
Choose National Bank of Poland API if its data fits your use case better; on access and reliability it's level with Fulusly API.

	Fulusly API	National Bank of Poland API
What it does	Exchange rates for 144 currencies with daily history back to the 1990s, English and Arabic.	A collection of currency exchange rates (data in XML and JSON).
Provider	Fulusly	NBP Web API
API key	Not needed	Not needed
HTTPS	Yes	Yes
CORS (browser calls)	Yes	Yes
Status today	Online · 486 ms	Online · 492 ms
Uptime (30 days)	Up	Up
Developer rating	Not rated yet	Not rated yet
Price	Free / free tier	Free / free tier

Exchange rates for 144 currencies with daily history back to the 1990s, English and Arabic.

Free currency-rates JSON API and an embeddable converter widget from Fulusly.

Strengths

A collection of currency exchange rates (data in XML and JSON).

NBP Web API allows HTTP clients to make enquiries on datasets published by the NBP.PL

Strengths

Prototyping or a tutorial? Pick the one that needs no API key (both qualify).
Calling from a web page? You need CORS. Otherwise route requests through your own server or a serverless function.
Going to production? Favour HTTPS, a strong uptime record and a provider with clear rate limits and terms. Check each API's docs before you commit.
Still unsure? Both are free to try: send one request to each and compare the data you get back.

Neither needs an API key; you can call both straight away.