For developers

A free rates API.

Every rate the app uses lives in one JSON file. Point your code at it and read the numbers. No key, no sign-up, no rate limit.

GEThttps://curren.cy/data/rates.json

FreeNo API keyNo rate limit

Quick start

Fetch it

curl https://curren.cy/data/rates.json

Read a rate

const res = await fetch("https://curren.cy/data/rates.json");
const { ecb } = await res.json();

// ECB reference rates, keyed by ISO 4217 code (EUR = 1)
ecb.rates.USD; // 1.1401

Convert any pair

// Convert 100 GBP to JPY. The base currency doesn't matter —
// any pair works with: amount * rates[to] / rates[from]
const { rates } = ecb;
const jpy = 100 * rates.JPY / rates.GBP; // ≈ 21368

The response

One file holds both sources. Each has its own base currency and publish date, so you can pick the one you trust and read its rates map.

{
  "fetchedAt": "2026-06-28T05:30:00.000Z",
  "ecb": {
    "base": "EUR",
    "date": "2026-06-26",
    "rates": { "EUR": 1, "USD": 1.1401, "JPY": 184.3, "GBP": 0.86253, ... }
  },
  "currencyApi": {
    "base": "USD",
    "date": "2026-06-27",
    "rates": { "USD": 1, "EUR": 0.8782, "JPY": 161.7, "GBP": 0.7566, ... }
  }
}

Good to know

Two sources in one file: ecb (European Central Bank, EUR base, updated on working days) and currencyApi (an open exchange-rate API, USD base, updated daily). Use whichever you prefer.
Rates are keyed by ISO 4217 code, and the base currency is always 1.
Convert any two currencies with amount × rates[to] / rates[from] — the base currency cancels out, so it doesn't matter which source you pick.
Refreshed twice a day. Read date for each source, or fetchedAt for when the file was last built.
ecb lists the euro and 29 reference currencies; currencyApi covers 300+ currencies (including crypto), so use it when you need a code the ECB doesn't publish.
These are reference rates for everyday use, not settlement prices or financial advice — see the Terms of Use.

It's free with no key and no rate limit. More rate sources may be added later.