Fixer vs Open Exchange Rates: two locked-down free tiers, compared honestly
Both vendors are established. Both cap their free tier hard. Fixer locks you to EUR at 100 calls a month; Open Exchange Rates locks you to USD at 1,000 calls a month and gates conversion and time-series behind a paid plan. The restrictions look similar until you map them against what you actually need.
Fixer's free plan gives 100 calls a month with the base fixed to EUR. Open Exchange Rates gives 1,000 calls a month with the base fixed to USD, and reserves multiple base currencies, time-series, and conversion requests for paid plans starting at $12/month. Picking between them starts with which base currency you actually need and how many calls you'll burn. Figures here were checked directly against each vendor in August 2026 — confirm current terms before committing, since free-tier limits move.
The same shape, locked in different places
Fixer and Open Exchange Rates are both mature, well-documented services with years of production behind them — neither the scrappy newcomer. What separates them on the free tier is which capability each vendor decided to hold back until you pay.
Fixer's free plan: 100 calls a month, EUR-only base, hourly updates, historical data and SSL included, no conversion. Open Exchange Rates' free plan: 1,000 calls a month, USD-only base, hourly updates, daily historical data — but multiple base currencies, time-series, and conversion are excluded until you upgrade.
The base-currency trap, from two directions
This is the crux of the comparison. Fixer pins its free base to EUR; Open Exchange Rates pins its free base to USD. A EUR-denominated project fits Fixer, not Open Exchange Rates — you'd pay from $12/month just to quote from EUR. Flip the currency and it reverses.
What else sits behind the paywall
Fixer's free-plan exclusion list is short: no conversion endpoint, no base currency besides EUR. Everything else — hourly updates, historical data, SSL — ships free.
Open Exchange Rates' free-plan exclusion list runs longer: multiple base currencies, time-series, and conversion are all withheld. A project charting a currency pair's movement over a month, not just today's snapshot, can't do that on the free tier — time-series is paid-only there. Fixer includes historical data on free, a related but distinct capability; check which one your integration needs.
Working the call-volume math
Ten times the quota sounds decisive, but run the numbers against your actual use first. A once-daily cron job checking a handful of pairs uses well under 100 calls a month — Fixer's free tier covers it with room to spare, and the EUR restriction is irrelevant if EUR is already your base.
A dashboard refreshing rates on every page load burns through 100 calls in a day at modest traffic, and 1,000 calls within two or three weeks at the same rate. Neither free tier survives real page-load traffic for long. At that point the question becomes "which paid tier costs less" — and that's where Open Exchange Rates' $12/month entry point versus Fixer's Basic tier pricing decides it, not the free-tier quota gap.
Picking one, given a specific need
Base currency is EUR, call volume is light, and you don't need time-series or conversion yet: Fixer's free plan is the direct fit — exactly what a EUR-based prototype needs without paying for anything.
Base currency is USD, and your integration needs more headroom than 100 calls a month gives: Open Exchange Rates' free tier, at 1,000 calls, is the better starting point — as long as you don't need time-series or conversion, since both are paid-only there.
You need time-series data specifically, on a tight budget: Fixer includes historical data on its free plan; Open Exchange Rates does not include time-series requests at all. That single distinction can decide the comparison if charting or backtesting is core to what you're building.
You need conversion built in, without writing the arithmetic yourself: neither vendor's free plan has it. Both push conversion to a paid tier, so this factor is a wash and shouldn't break the tie.
Once you're past the free tier
If neither free plan survives your actual traffic and $12/month or more feels premature, exchangerate.dev's free tier offers 10,000 calls a month with no base-currency restriction and no card required — worth a look alongside Fixer's Basic tier and Open Exchange Rates' paid plans.