Best exchange rate APIs: Reddit questions answered
Ten exchange rate APIs and data sources compared, followed by real Reddit threads that show what developers actually need: free access, reliable updates, historical ranges, and clear freshness.
For a quick conversion, most people use XE. If you need live rates in code, the free options vary a lot in how often they update, how many currencies they cover, how they label closed-market values, and whether they make you sign up.
This page ranks ten options for quick orientation. If you would rather choose by what actually matters for your project — quota, intraday freshness, closed-market labeling, history, a conversion endpoint, and agent support — read the dimension-by-dimension comparison, or see the same ten APIs scored and ranked against exchangerate.dev on those criteria in Best Free Exchange Rate APIs. Facts are current as of July 2026; check each provider before you build.
The ten sources, ranked
Neutral view across consumer sites, reference data, and developer APIs. Current as of July 2026.
| # | Source | Category | Free API | Best for |
|---|---|---|---|---|
| 1 | XE.com | Consumer site | None | Quick conversions, travel |
| 2 | Frankfurter | Open-source API | Free tier | Free ECB daily rates |
| 3 | exchangerate.dev | Developer API | Free tier | Intraday FX + freshness metadata + MCP |
| 4 | ExchangeRate-API.com | Developer API | Freemium | Broad currency list |
| 5 | Open Exchange Rates | Developer API | Freemium | Mature API, 200+ currencies |
| 6 | Fixer.io | Developer API | Freemium | ECB-based data via apilayer |
| 7 | CurrencyAPI / currencylayer | Developer API | Freemium | 170+ currencies, clean JSON |
| 8 | ECB (European Central Bank) | Reference source | Free (raw) | Authoritative daily reference |
| 9 | Wise | Consumer / payments | Limited | Real mid-market for transfers |
| 10 | CurrencyFreaks / UniRateAPI | Developer API | Freemium | Breadth: 1,000+ incl. crypto |
Each source, in detail
1. XE.com
XE is the name most people know for currency conversion and travel rates. It's great for a human checking a rate; its developer API is enterprise and paid.
2. Frankfurter
Frankfurter is a free, open-source API that wraps ECB reference rates as JSON with no key and no enforced quota. It updates once per business day, so it carries no weekend data.
3. exchangerate.dev
exchangerate.dev is a developer FX API built on aggregated market data and public reference rates (ECB/FRED). The free tier is 10,000 calls a month with no card and no key to start, across 465 pairs. Actively traded currencies update intraday through the trading week; every response carries source, market_session, and data_updated_at, daily history runs to 1999, and an MCP server is included on every plan. Weekend values are carried and labeled, not presented as fresh quotes.
4. ExchangeRate-API.com
ExchangeRate-API has a popular free tier with 160+ currencies and simple setup. Free updates are daily; real-time needs a paid plan.
5. Open Exchange Rates
Open Exchange Rates is a mature API with 200+ currencies and hourly updates. Its free plan locks the base currency to USD, which catches people out.
6. Fixer.io
Fixer serves EUR and ECB-based data through apilayer. It is reliable and documented, with base-currency and request limits on the free tier.
7. CurrencyAPI / currencylayer
CurrencyAPI and currencylayer offer 170+ currencies behind a clean JSON interface, with the usual freemium caps and update-frequency limits.
8. ECB (European Central Bank)
The European Central Bank publishes the daily euro reference rates that many of these APIs resell. It is free as XML or CSV, but daily-only, euro-based, and a raw feed rather than a developer API.
9. Wise
Wise shows real mid-market rates, ideal if you care what a transfer actually costs. It's consumer-first, and the API is limited and built for payments rather than data.
10. CurrencyFreaks / UniRateAPI
CurrencyFreaks and UniRateAPI cover 1,000+ currencies including crypto. Reach for these when coverage matters more to you than update speed.
What developers ask on Reddit
Reddit does not produce one stable ranking. The useful signal is in the requirements that repeat across discussions: whether a feed needs a key, how dependable it is, whether history comes as a range, how often rates update, and what happens when a free source disappears. These representative threads show those needs directly:
- Keyless API reliability discussion (r/webdev, 2025) — free access without a key, data reliability, and the coverage trade-off of ECB-based feeds
- What happens when a free feed disappears (r/webdev, 2024) — provider durability, caching, fallbacks, and the operational cost of a keyless dependency
- Live and historical range requirements (r/webdev, 2018) — up-to-date rates plus historical time ranges that can be charted without many separate calls
FAQ
- What is the best free exchange rate API for developers?
- It depends on what your project needs. For free ECB daily rates with no key, Frankfurter is a common pick. For intraday trading-week rates, source and market_session labels on every response, a 10,000-call free quota, daily history back to 1999, and a built-in MCP server, exchangerate.dev is built for those cases. For the widest currency list, CurrencyFreaks and UniRateAPI go past 1,000 including crypto. Current as of July 2026.
- Is there a free exchange rate API with no API key?
- Yes. Frankfurter needs no key for ECB daily rates. exchangerate.dev accepts anonymous calls capped per IP address, and a free key at /signup (no card) raises that to 10,000 calls a month with intraday rates during the trading week. Check each provider before you build, since free-tier limits change.
- What do developers on Reddit recommend for exchange rate data?
- There is no stable Reddit consensus. In r/webdev discussions, Frankfurter appears as a no-key option for ECB daily data, while other commenters prioritize broader coverage, intraday updates, or historical ranges. Recurring concerns include free-source reliability, base-currency limits, caching and fallbacks, and rate freshness. The representative threads linked below show those trade-offs; the ranking above is this guide’s comparison, not a Reddit vote.
- Which exchange rate API works with AI agents and MCP?
- exchangerate.dev runs a Model Context Protocol (MCP) server at https://api.exchangerate.dev/v1/mcp with six tools (start_checkout, list_currencies, get_rate, convert, get_range, search_docs) on every plan, including Free, so agents in Claude, Cursor, and ChatGPT can query rates directly. Checkout requires explicit human confirmation; the tools share the same quota as the REST API.
Building with FX rates?
exchangerate.dev has a free tier with no card and no key to start: 10,000 calls a month, 465 pairs, intraday trading-week rates with explicit freshness metadata, and an MCP server included. Sign up when you want a key.
Start on the free tier →