Choosing the right currency API can make or break your application's accuracy and reliability. Whether you are building a fintech dashboard, an e-commerce checkout, or a SaaS billing system, you need an API that delivers accurate rates, affordable pricing, and a smooth developer experience. We evaluated the five most popular currency APIs available in 2026 across key criteria to help you make the right choice.
Quick Comparison
| API | Free Tier | Update Frequency | Base Currency | SDKs | Starting Price |
|---|---|---|---|---|---|
| Exchange Rate API | 300 req/mo | 60 seconds | Any (160+) | JS, Python, PHP, React | Free / $4.99/mo |
| ExchangeRate-API | 1,500 req/mo | Daily | Any | None official | Free / $7.99/mo |
| Frankfurter | Unlimited | Daily (ECB) | ECB currencies only | None | Free (open-source) |
| Currencylayer | 100 req/mo | Hourly (paid) | USD only (free) | None official | Free / $14.99/mo |
| Fixer | 100 req/mo | Hourly (paid) | EUR only (free) | None official | Free / $14.99/mo |
Exchange Rate API
Exchange Rate API delivers real-time mid-market exchange rates sourced from Reuters/Refinitiv interbank feeds, updated every 60 seconds. It covers 160+ currencies with a generous free tier and official SDKs for JavaScript, Python, PHP, and React. The API uses simple Bearer token auth, supports CORS for browser apps, and provides both latest and historical rate endpoints.
Pricing: Free (300 req/mo) | Small $4.99/mo (5K) | Medium $9.99/mo (10K) | Large $49.99/mo (100K)
Pros
- 60-second update frequency on all plans including free
- Any base currency on free tier (not locked to USD/EUR)
- Official first-party SDKs for 4 languages
- CORS support for browser-based apps
- Historical rates with multiple time ranges
- Clean, well-documented REST API
Cons
- Free tier limited to 300 requests/month
- No cryptocurrency support
- Newer provider (less brand recognition)
ExchangeRate-API
ExchangeRate-API is a well-established provider with a focus on simplicity. Their free plan offers 1,500 requests per month with daily rate updates. Paid plans unlock minute-level updates and higher limits. The API is straightforward but lacks official SDKs, leaving integration to community libraries or raw HTTP calls.
Pricing: Free (1,500 req/mo, daily) | Pro $7.99/mo (30K) | Business $15.99/mo (100K)
Pros
- Generous free tier (1,500 requests/month)
- Simple, easy-to-use API format
- Any base currency on all plans
- Good uptime track record
Cons
- Free tier limited to daily updates only
- No official SDKs
- No historical rates on free plan
- No CORS documentation
Frankfurter
Frankfurter is a free, open-source currency API powered by data from the European Central Bank. It requires no API key, has no rate limits, and is ideal for prototyping or non-commercial projects. However, it only covers about 30 ECB-published currencies and updates once daily around 16:00 CET.
Pricing: Completely free. No API key required. Open-source.
Pros
- 100% free with no API key required
- No rate limits whatsoever
- Open-source (self-hostable)
- Historical rates back to 1999
Cons
- Only ~30 ECB currencies (no exotic pairs)
- Daily updates only (once per day)
- No official support or SLA
- No SDKs or advanced features
Currencylayer
Owned by apilayer, Currencylayer has been in the market since 2014. It supports 168 currencies and offers historical rates, time-series, and conversion endpoints on paid plans. The free tier is heavily restricted with only 100 requests/month, USD-only base, and no HTTPS encryption.
Pricing: Free (100 req/mo, USD only, HTTP only) | Basic $14.99/mo | Pro $39.99/mo
Pros
- 168 currencies including some crypto
- Time-series and conversion endpoints
- Long track record (since 2014)
- Part of the apilayer ecosystem
Cons
- Free tier: 100 req/mo, USD only, no HTTPS
- Expensive paid plans for full features
- No official SDKs
- Hourly updates at best (not real-time)
Fixer
Fixer (fixer.io) is another apilayer product, formerly a popular open-source project. It supports 170 currencies with historical data going back to 1999. However, the free tier is extremely limited: 100 requests/month, EUR base only, no HTTPS. Paid plans start at $14.99/month for basic features most competitors include for free.
Pricing: Free (100 req/mo, EUR only, HTTP only) | Basic $14.99/mo | Pro $39.99/mo
Pros
- 170 currencies supported
- Historical rates back to 1999
- Well-known brand name
- Fluctuation and time-series endpoints
Cons
- Free tier: 100 req/mo, EUR only, no HTTPS
- No free HTTPS (security risk)
- No official SDKs
- Hourly updates at best
- Higher price for comparable features
Our Verdict
For most developers in 2026, Exchange Rate API offers the best combination of real-time accuracy (60-second updates), flexible pricing, official SDK support, and unrestricted base currencies. If you need zero-cost unlimited calls and only work with major currencies, Frankfurter is an excellent open-source alternative. For high free-tier volume with daily rates, ExchangeRate-API is worth considering.
Currencylayer and Fixer remain viable for enterprise use cases but their restrictive free tiers and higher pricing make them harder to recommend for indie developers and startups.
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