AllRatesToday vs Frankfurter: When Free ECB Rates Stop Being Enough

Let's start with something most API comparisons won't say: Frankfurter is genuinely good. It's free, open-source, keyless, unlimited, and it does exactly what it promises — serve the European Central Bank's reference rates over a clean JSON API. If you're building a prototype, a homework project, or a EUR-centric tool that needs ~30 major currencies once a day, use Frankfurter and don't look back.

This comparison is for the moment that stops being true. In our experience, developers don't leave Frankfurter because something better is advertised — they leave because they hit a wall it structurally cannot cross. There are five of them, and which one you hit first depends on what you're building.

At a glance

Frankfurter details are based on its public documentation at frankfurter.dev and may change. Check the project's site for the latest.

Wall 1: The currency list

Frankfurter serves the currencies the ECB publishes reference rates for — roughly 30 majors. The moment your app needs a Pakistani rupee, Sri Lankan rupee, Bangladeshi taka, Nigerian naira, Vietnamese dong, or Egyptian pound, Frankfurter has no answer at any price. There is no workaround: the data simply isn't in the dataset.

This is usually the first wall remittance apps, marketplaces with emerging-market sellers, and travel tools hit. AllRatesToday covers 160+ currencies including precisely those corridors — and its official-rates catalog leans deliberately toward South and Southeast Asian central banks that other providers skip.

Wall 2: One fixing per day

The ECB publishes its reference rate once per business day, around 16:00 CET — and states plainly that it's intended for reference, not transactions. If your checkout reprices in near real time, if you're monitoring a moving market, or if a user asks "what's the rate right now?" at 9am, yesterday afternoon's fixing is the wrong answer.

AllRatesToday serves real-time mid-market rates fetched live on each request. The difference isn't academic: on a volatile day a currency pair can move well over a percent between two ECB fixings.

Wall 3: Weekends don't exist

No ECB publication means no Frankfurter data on Saturdays, Sundays, or ECB holidays. Your app doesn't get weekends off — an e-commerce site sells all weekend, and "rate as of Friday afternoon" silently drifts from the market until Monday. AllRatesToday serves current rates every day of the year, and its official-rates endpoints handle non-publication days properly: they return the most recent published table with the bank's own rate_date and an explicit flag, which is exactly what compliance rules expect.

Wall 4: The ECB is only one of the world's central banks

This is the wall that surprises people. Frankfurter gives you official rates — but only the ECB's. Official-rate requirements are jurisdictional: a UK customs declaration cites HMRC's monthly rate, a US government filing cites the US Treasury's quarterly rate, an Indian invoice references the RBI, a Brazilian one PTAX. The ECB rate is simply the wrong number for all of those.

AllRatesToday serves the published tables of 83 central banks and 3 tax authorities through one API — the Fed, Bank of England, People's Bank of China, RBI, HMRC, US Treasury and dozens more, with history reaching back decades (and every computed cross-rate explicitly flagged as derived, because for compliance work the published/derived distinction matters). Over a recent year, the widest gap between the live GBP/USD market rate and HMRC's official rate-in-force was 3.7% — real money on a real invoice. More on that in our tax authority rates guide.

Wall 5: Nobody is on the hook

Frankfurter is a volunteer-run open-source project. That's admirable — and fine for a side project. But when a business books revenue, closes months, or settles invoices off a rate feed, someone needs to be answerable when the feed misbehaves. "Self-host it if you need an SLA" converts a €4.99/month problem into an ops responsibility with pager duty. Paid infrastructure exists precisely because accountability is a feature.

What switching looks like

The APIs are close enough that migration is usually under an hour. A Frankfurter call:

GET https://api.frankfurter.dev/v1/latest?base=USD&symbols=EUR,GBP

becomes:

GET https://allratestoday.com/api/v1/rates?source=USD&target=EUR,GBP
Authorization: Bearer art_live_your_key

Response shapes differ slightly (Frankfurter returns a rates map; AllRatesToday returns an array of rate objects with timestamps), but the concepts — base, targets, historical dates — map one to one. Official SDKs for JavaScript, Python, PHP and Rust remove even that step, and the full mapping lives on our Frankfurter alternative page.

The honest verdict

Frequently Asked Questions