Currency Converter is the one tool on this site that needs a network connection — live exchange rates can't be computed locally, since they change throughout the day. It fetches a public daily rate snapshot at most once every 24 hours and caches it locally, so every conversion you make afterward is computed instantly from that cached snapshot with no further network requests.

The rate request itself carries no user data: it's a plain, anonymous request to a public endpoint. The amount and currencies you enter stay entirely in your browser. If you're offline or the rate request fails, the converter falls back to the last cached snapshot and clearly labels it as offline data rather than failing outright.

The 24-hour cache window is a deliberate trade-off, not an arbitrary number. Exchange rates do move throughout the day, but for the kind of everyday use this tool is built for — estimating a travel budget, sanity-checking an invoice, converting a price you're comparing across two stores — intraday fluctuations are rarely the deciding factor, and re-fetching on every single conversion would mean a network round trip (and a wait) every time you tweaked an amount. Caching for a day means the tool feels instant for repeated use while still staying reasonably current, and the cached snapshot is stored in your browser's own local storage (IndexedDB), not on any server, so it persists across page reloads without needing to be fetched again.

This is also the one tool on the site with an explicit, documented exception to the "zero network requests" rule that governs every other tool here — see the Privacy Policy for the full detail on exactly what that request does and doesn't send.

For anything time-sensitive — an actual currency exchange, a wire transfer, a trade — use your bank or a dedicated financial service for a live, guaranteed-current rate; this tool is meant for quick estimates, not execution-grade pricing.