Methodology & data sources
FXCorridor shows mid-market (interbank) exchange rates derived from European Central Bank reference rates, fetched through the free Frankfurter API and stored as a dated JSON snapshot (current snapshot: 2026-06-13). A cross rate from currency A to B is computed as the USD rate of B divided by the USD rate of A. We do not add any margin — but we make clear that banks and transfer services do, so the rate you receive will be slightly worse.
Source: open.er-api.com (free, no-key aggregated mid-market reference rates), ECB via Frankfurter as fallback. Data as of 2026-06-13.
Data sources
| Source | Refresh cadence | License |
|---|---|---|
| European Central Bank reference rates (via Frankfurter API) | daily | Free to use; rates published by the European Central Bank. |
How the rates are fetched
A small Node script (scripts/fetch-data.mjs) calls the Frankfurter API
(https://api.frankfurter.app/latest?from=USD, no API key), normalises the response
to a base-USD rate map, validates that every tracked currency is present and within a plausible
range, and writes src/data/rates.json. The committed JSON keeps the build
deterministic; a scheduled GitHub Action refreshes it and commits any change, which triggers a
rebuild. No network calls happen at build time.
How conversions are computed
All rates are stored as units of a currency per 1 USD. To convert an amount x from
currency A to currency B we compute
x × (rate_B / rate_A). The converter performs the same arithmetic in your browser,
so nothing you type is sent anywhere.
Mid-market vs the rate you get
The rates here are wholesale midpoints. Retail providers apply a spread (typically 0.5%–5%) and may charge a fixed fee, so the effective rate is worse than the mid-market rate. Always compare the total amount the recipient receives.
Limitations
Rates move continuously during market hours; our snapshot reflects a single point in time and may lag the market. The recent-trend tables on pair pages use illustrative seed values and are not an authoritative historical series. Figures are for general information only — see our disclaimer and verify against the primary source before relying on them for a transaction.
Last updated: 2026-06-13