Currency Converter (Live)

Overview

Convert amounts between roughly 160 currencies using public daily reference rates fetched without an API key. The tool always shows which rate source is in use and its update date, caches the last result for 12 hours, and keeps a dated fallback table for offline use.

How It Works

Enter an amount, choose From and To currencies, and read the converted result plus the unit rate. The status line names the active source and update date, and a Refresh live button forces a fresh fetch.

Step-by-Step Usage Guide

1. Type an amount into the input field; conversion recalculates immediately against the current rate.
2. Pick the From and To currencies from the two selects; about 160 are available when live.
3. Read the converted result and unit rate, then check the status line for the source and date.
4. Enter your bank's exact rate in the override field when you have one, or press Refresh live to fetch new rates.

Technical Specifications & Standards

Rates come from open.er-api.com/v6/latest/USD and, if that fails, a CDN-hosted open currency API. Every page load fetches fresh rates; successful responses are also cached in localStorage with a 12-hour TTL, and that cache fills the screen while the fetch is in flight or if it fails. If both fetches fail and no fresh cache exists, a bundled table of 14 major currencies dated 2026-08-29 takes over; the status line then reads 'Offline fallback rates (bundled, <date>) — live fetch failed', and a still-fresh cached table shown after a failed fetch carries the same label with its own date. A manual override field accepts your bank's exact rate and wins whenever it is filled.

Targeted Use Cases

• Budgeting a trip: convert a daily spending amount and confirm from the status line whether rates are live or offline fallback.
• Invoicing a foreign client: apply your bank's actual rate in the override field so the quoted figure matches what the payment will settle at.
• Comparing to your bank: leave the override empty to see the daily reference rate, then fill the override with your bank's quoted rate to see the gap.
• Working offline: after both fetches fail, the 14-currency dated fallback keeps major pairs usable while the status line discloses the limitation.

Notes & Gotchas

• Treat every result as an estimate. Daily reference rates are not the rate you will actually get; cards and banks add margins the tool cannot model because there is no percentage-fee input.
• Use the override field for real quotes. A rate you enter there wins over the fetched rate while it is filled, so clear it to return to live values (changing either currency also clears it).
• Check the status line before trusting a number. The offline fallback message means only 14 majors are available and the bundled date may be old.
• Press Refresh live after the network returns; rates are also fetched again on every page load. There is no inverse-rate display.

Frequently Asked Questions