exchangerate.devFixer Free gives 100 calls a month with no base-currency changes or conversion endpoint. ExchangeRate-API offers a keyed free tier at 1,500 calls a month, or a keyless daily endpoint requiring visible attribution. Neither is a strict upgrade; they solve different problems. Limits checked against Fixer's pricing and ExchangeRate-API's free-access documentation on September 15, 2026; Fixer's base rule rechecked October 17, 2026.
- Fixer free: 100 calls/month, hourly updates and historical data for non-commercial use; no base-currency changes or conversion endpoint.
- ExchangeRate-API keyed free: 1,500 calls/month with a pair-conversion endpoint. Both free routes update once daily; open access requires no key.
- Open-access ExchangeRate-API calls require visible attribution and forbid redistributing the data; caching is fine.
- Fixer Free cannot change the base currency; ExchangeRate-API does not restrict base currency on either of its free options.
- Rate-limited open-access calls return HTTP 429 and the restriction clears after 20 minutes.
- For a project needing to choose its base at low volume, ExchangeRate-API allows any base on both free options; Fixer adds all base currencies on Basic.
Two different shapes of free
Fixer's free plan is listed at 100 calls a month with hourly updates, SSL, and historical data included. The pricing table excludes base-currency changes on Free. Basic includes all base currencies and the conversion endpoint.
ExchangeRate-API splits its offering in a way Fixer does not: a keyed free tier at 1,500 calls a month, and a separate open-access endpoint at open.er-api.com needing no key or signup. Both free routes update once per day rather than hourly; open access carries its own attribution terms, covered below.
1,500 calls beats 100 by a wide margin, but Fixer's 100 calls update hourly and include historical data; ExchangeRate-API's keyless option updates once daily. Compare cadence and quota together.
Base currency: the constraint that decides for you
Fixer's pricing table excludes base-currency changes on Free. Basic includes all base currencies. ExchangeRate-API documents its free options as unrestricted by base.
ExchangeRate-API documents no base-currency restriction on either free option. If your project needs to choose a base, both free options support that; Fixer requires Basic for base-currency changes.
Conversion: built in, or do the math yourself
Fixer's free plan has no conversion endpoint. You get a table of rates and write the multiplication yourself, one line of arithmetic, but worth knowing before you go looking for a /convert call in Fixer's free docs.
ExchangeRate-API's keyed Pair Conversion endpoint is included in its Free plan and accepts an optional amount. The keyless open-access endpoint returns a rate table, so you calculate the amount yourself on that path.
Attribution and redistribution: the strings attached to "free"
Fixer lists its Free plan for non-commercial use; check the commercial license before using it in a customer product. Its pricing page does not state an attribution requirement. ExchangeRate-API permits commercial use of its open-access endpoint with a visible credit line and live link, but forbids redistributing the raw feed.
That attribution requirement affects the product surface. A backend service or batch job with no user-facing page has nowhere natural to put "Rates By Exchange Rate API." ExchangeRate-API documents no attribution requirement for its keyed Free plan. Fixer's pricing does not state an attribution rule; check the license for your use case.
| Factor | Fixer (free) | ExchangeRate-API (free) |
|---|---|---|
| Monthly quota | 100 calls | 1,500 calls (keyed) or unmetered-with-limits (keyless open-access) |
| Base currency | Cannot be changed on Free | Not restricted on either free option |
| Update cadence | Hourly | Once daily (both free routes) |
| Conversion endpoint | Not on free plan | Pair Conversion on keyed Free; keyless open access returns rates |
| Attribution required | Not stated for free tier | Required on the keyless open-access endpoint |
| Commercial use | Free plan listed as non-commercial | Permitted on open access with attribution; check keyed terms |
| Key required | Yes, always | No for open-access; yes for the 1,500/month keyed tier |
What happens when you go over
ExchangeRate-API's open-access endpoint returns HTTP 429 once you exceed its rate limit, and the restriction lifts after 20 minutes, a documented, predictable window worth building retry logic around rather than guessing.
Fixer lists a monthly Free allowance of 100 calls. Its public pricing page does not specify the exact over-limit response or reset timing. Test the error on your account and monitor the quota rather than assuming the same 20-minute behavior as ExchangeRate-API's open-access endpoint.
Verdicts by use case
A prototype you're building over a weekend, testing a rate-table response: Fixer's 100 calls a month is enough to poke at the API and see the response shape. You won't run load tests, but you don't need to yet.
Once real users arrive, even a handful, 100 calls a month runs out fast. ExchangeRate-API's 1,500-call keyed tier, or its once-daily open-access endpoint if daily-only freshness works for you, both outlast Fixer's free plan here.
If you need to choose a base currency, Fixer Free cannot do that. ExchangeRate-API documents no base restriction on either free path, so either supports that requirement without a paid plan.
Cannot display attribution anywhere a user or operator would see it? ExchangeRate-API's open-access endpoint is disqualified by its own terms, the credit line and link are required. Its keyed 1,500-call tier drops that requirement, and so does paying for Fixer. Between those two, the choice comes down to quota and base currency again.
100 calls and 1,500 calls are both prototyping-scale numbers next to a production app with real users. Treat either free tier as a place to validate an integration, not to run it indefinitely.
When neither free tier holds up
If your call volume outgrows 100 or 1,500 a month, or you need intraday updates (15 minutes late on Free) with any supported base, exchangerate.dev's free tier gives 5,000 calls a month with no card required and no base-currency restriction; one more option worth checking alongside Fixer's and ExchangeRate-API's paid plans.