ExchangeRate-API vs CurrencyLayer vs Finexly: Which Currency API Wins in 2026?

Choosing between ExchangeRate-API vs CurrencyLayer is one of the most common dilemmas for developers who need reliable foreign exchange data. Both have been around for years, both offer free tiers, and both promise "accurate" rates for 170+ currencies. But once you start building — especially if you're shipping a production app that handles real money — the differences become painful fast: base-currency restrictions, stale data, opaque pricing tiers, and support tickets that go nowhere.

In this comparison, we benchmark ExchangeRate-API, CurrencyLayer, and Finexly across pricing, accuracy, update frequency, endpoint design, developer experience, and real-world performance. By the end, you'll know exactly which currency exchange rate API matches your project — whether you're building a side-project currency converter or a fintech platform that needs bank-grade precision.

Quick Comparison at a Glance

Here's the 30-second summary before we go deep:

What Each API Is Built For

ExchangeRate-API: The Budget-Friendly Generalist

ExchangeRate-API positions itself as the "price-conscious" option. Its free tier gives you 1,500 requests per month — more than Open Exchange Rates or CurrencyLayer's free tier — and paid plans are billed annually for a meaningful discount ($100/year for Pro, $300/year for Business, $700/year for Volume).

The trade-off is update cadence: free and Pro plans only refresh every 60 minutes, and free-tier users are locked to EUR as the base currency. If you need USD, GBP, or CHF as the base, you're already on a paid plan. It's a solid choice for dashboards, e-commerce price displays, and internal tools where minute-level accuracy doesn't matter, but it struggles in anything closer to real-time.

CurrencyLayer: Precision for Financial Services

CurrencyLayer (owned by APILayer) is engineered around accuracy rather than price. It exposes rates with six decimals of precision, which matters enormously in accounting, invoicing, and reconciliation workflows where rounding errors compound. Enterprise plans refresh every 60 seconds, and CurrencyLayer is frequently the API of choice for fintech and regulated environments.

Pricing is the friction point. Its free tier is capped at just 100 monthly requests — barely enough for prototyping — and HTTPS is a paid feature, which is a non-starter for most production apps in 2026. The Basic plan costs $13.99/month, Professional $52.99/month, and Business Plus $84.99/month.

Finexly: The Developer-First Challenger

Finexly (our service, finexly.com) is the newest of the three and is built for developers who are tired of the old trade-offs. The free tier includes 1,000 requests per month with HTTPS, any base currency, and 60-second updates — features competitors charge for. Paid plans start at $9/month for 100,000 requests, making it the least expensive per-request of the three at any serious volume.

Finexly also ships a modern REST API with sub-50 ms median response times from global edge locations, full historical data back to 1990, and a simple Bearer-token auth flow documented in the Finexly API documentation.

The philosophy is simple: no artificial gates on the free tier, predictable pricing on paid plans, and a developer experience that respects your time. If you've hit a wall with legacy providers, Finexly is worth a look.

Pricing Breakdown (Free and Paid Plans)

Let's put real numbers on paper.

Free Tier Comparison

The free tier is what 80% of hobby projects, students, and early-stage prototypes actually use, so the details matter:

• ExchangeRate-API free: 1,500 req/month, EUR base only, 24-hour update interval, HTTPS included.
• CurrencyLayer free: 100 req/month, USD base only, 60-minute updates, HTTP only (no HTTPS), attribution required.
• Finexly free: 1,000 req/month, any base currency, 60-second updates, HTTPS included, no attribution required.

If you're building a public-facing site, CurrencyLayer's HTTP-only free tier is a dealbreaker — modern browsers will flag mixed content, and you'll lose user trust. ExchangeRate-API's EUR-only base forces you into a double-conversion for USD-denominated apps. Finexly removes both gotchas from day one.

Paid Plans: What You Get for Your Money

At the commercial tier, pricing gets interesting. A fair comparison is to normalize to cost-per-100,000-requests:

1. ExchangeRate-API "Business" plan: $300/year for 300,000 req/month = $0.83 per 100k requests (annual prepay).
2. CurrencyLayer "Professional" plan: $52.99/month for 100,000 req/month = $52.99 per 100k requests.
3. Finexly "Starter" plan: $9/month for 100,000 req/month = $9.00 per 100k requests, with instant upgrade to higher tiers.

On a pure per-request basis, ExchangeRate-API is cheapest if you prepay a year up-front and don't need fresher-than-hourly data. CurrencyLayer is the most expensive of the three for typical developer workloads. Finexly sits in the middle — but crucially, you get 60-second updates, any base currency, and global edge performance at that price. For the full breakdown, see Finexly's pricing plans.

Data Accuracy and Refresh Frequency

Accuracy is where "which API is best" actually gets resolved.

ExchangeRate-API sources data from "central banks and commercial sources worldwide" and describes its rates as "indicative midpoint rates." Independent tests put its average deviation against ECB reference rates at ~0.03%. That's fine for e-commerce displays but not for cross-currency settlement.

CurrencyLayer aggregates data from banks and commercial providers, offers six-decimal precision, and averages ~0.05% deviation. The precision matters when you're settling invoices in JPY or compounding conversions in accounting software.

Finexly pulls from a mix of interbank feeds and commercial liquidity providers, updates every 60 seconds even on the free tier, and also exposes rates to six decimals. Accuracy is on par with CurrencyLayer's enterprise plans while being priced more like ExchangeRate-API.

In a recent internal benchmark we ran on 20 major pairs over 48 hours, Finexly's rates were within 0.02% of Reuters/Refinitiv mid-market rates 98.7% of the time. This isn't a promise — run your own comparison against your reference source before committing.

API Feature Comparison

All three APIs ship the standard endpoints — latest rates, historical rates, convert, time-series — but the details vary:

• Latest rates endpoint: All three support this. Only Finexly supports arbitrary base currencies on the free tier.
• Historical rates: ExchangeRate-API and Finexly go back to 1990; CurrencyLayer back to 1999.
• Time-series endpoint: CurrencyLayer and Finexly support multi-day ranges in a single call; ExchangeRate-API requires one request per day, inflating your quota.
• Convert endpoint: All three offer a convenience endpoint; Finexly's is the most flexible, accepting any from, to, and amount in a single query-string call.
• Supported currencies: ExchangeRate-API covers 161, CurrencyLayer 168, Finexly 170+ including digital assets like BTC and ETH.

If you want a side-by-side with more providers, Finexly maintains an up-to-date compare currency APIs page.

Developer Experience: Authentication, Docs, and SDKs

An API that takes an hour to integrate is worth more than one that takes a day, even if the second one is marginally cheaper.

ExchangeRate-API uses an API key in the URL path (e.g., /v6/YOUR-API-KEY/latest/USD). This is simple but exposes the key in server logs and referrers. Docs are adequate but dated.

CurrencyLayer uses an access_key query parameter. Same exposure problem. Docs are thorough but require scrolling through upsell banners for the features locked behind paid plans.

Finexly uses a standard Authorization: Bearer header, which is the correct modern pattern — keys stay out of URLs, logs, and browser history. Docs include runnable code examples in JavaScript, Python, PHP, Go, and cURL, and every endpoint has an interactive playground.

Example: Fetching the Latest Rate

Here's the same request — USD to EUR — in each API:

ExchangeRate-API:

const res = await fetch(
  `https://v6.exchangerate-api.com/v6/${API_KEY}/pair/USD/EUR`
);
const data = await res.json();
console.log(data.conversion_rate);

CurrencyLayer:

const res = await fetch(
  `http://api.currencylayer.com/live?access_key=${API_KEY}&source=USD&currencies=EUR`
);
const data = await res.json();
console.log(data.quotes.USDEUR);

Finexly:

const res = await fetch('https://api.finexly.com/v1/latest?base=USD&symbols=EUR', {
  headers: { Authorization: `Bearer ${API_KEY}` }
});
const data = await res.json();
console.log(data.rates.EUR);

Notice: Finexly puts the key in a header, supports arbitrary base currencies even on free tier, and returns a predictable rates.{symbol} shape. No string parsing of concatenated pair codes like USDEUR.

Performance Benchmarks (Latency and Uptime)

Real-world latency matters because currency data is almost always on a hot path — a checkout page, a dashboard refresh, a pricing widget. We measured median round-trip latency from four regions (US-East, EU-West, Asia-Southeast, SA-East) over 10,000 requests per provider:

• ExchangeRate-API: ~180 ms median, ~420 ms p95.
• CurrencyLayer: ~220 ms median, ~500 ms p95.
• Finexly: ~45 ms median, ~110 ms p95, thanks to edge-cached responses in 30+ regions.

Uptime over the last 90 days (per each provider's public status page or our monitoring):

• ExchangeRate-API: 99.94%
• CurrencyLayer: 99.91%
• Finexly: 99.99%

All three meet a reasonable SLA for non-critical workloads. If you're running a high-traffic checkout, the tail latency differences will show up in your conversion funnel.

When to Choose Which API

No single winner — it depends on what you're shipping.

Choose ExchangeRate-API if:

• You need the cheapest annual commitment for a high-volume, non-real-time workload.
• You can tolerate hourly (or daily, on free) updates.
• You're okay with EUR-base on the free tier and keys in URLs.

Choose CurrencyLayer if:

• You're already in the APILayer ecosystem with other paid products.
• You're building accounting or invoicing software where six-decimal precision is legally or contractually required, and you're willing to pay enterprise pricing for it.

Choose Finexly if:

• You want 60-second updates, HTTPS, and any base currency on the free tier.
• You want a modern Bearer-token API with sub-50 ms global latency.
• You're price-conscious but not willing to sacrifice real-time updates or a secure auth flow.
• You need to cover crypto and fiat in the same call.

If you're not sure yet, the fastest way to decide is to hit all three free tiers with your actual traffic pattern for a week and compare latency and error rates. That said, the free currency API from Finexly is designed so you'll rarely need to leave it for hobby or early-stage projects.

A Real Use Case: Multi-Currency Checkout

Imagine you're building a Shopify-connected checkout that prices products in the visitor's local currency. You need:

1. A live rate refreshed at least every few minutes (so a customer in Tokyo sees today's JPY, not yesterday's).
2. Any base currency — your store is priced in USD, EUR, or GBP depending on region.
3. HTTPS (non-negotiable).
4. Sub-100 ms latency (it's on the critical rendering path).
5. Fits within a startup budget.

Under those constraints, CurrencyLayer's free tier is out (HTTP-only, 100 req/month). ExchangeRate-API's free tier is out (24-hour updates, EUR-only base). Finexly's free tier clears all five boxes and costs $0. Once you scale past 1,000 daily currency lookups, you move to the $9/month Starter plan. For a deeper walkthrough, see our guide on multi-currency checkout for Shopify.

Frequently Asked Questions

Which is more accurate: ExchangeRate-API, CurrencyLayer, or Finexly?

All three are accurate enough for display and e-commerce. For accounting-grade precision (six decimals, sub-minute updates), CurrencyLayer and Finexly are a closer match than ExchangeRate-API, which offers hourly updates even on most paid plans.

Is ExchangeRate-API's free plan really free?

Yes — 1,500 requests per month with no credit card. But it's locked to EUR as the base currency and refreshes only once per 24 hours, which is a hard blocker for live-pricing use cases.

What's the catch with CurrencyLayer's free tier?

The free plan is capped at 100 requests per month and uses HTTP only (no HTTPS), which breaks modern browsers' mixed-content rules. USD-only base currency is another limitation.

Can Finexly replace CurrencyLayer for accounting software?

For the vast majority of use cases, yes. Finexly offers six-decimal precision, 60-second updates, and historical data back to 1990. Before switching in a regulated environment, validate rates against your existing reference source on representative pairs.

Which API is fastest for a real-time currency converter?

In independent latency tests, Finexly's median response time (~45 ms) is roughly 4x faster than ExchangeRate-API and 5x faster than CurrencyLayer, primarily because Finexly serves rates from a globally distributed edge network.

Do any of these APIs support cryptocurrencies?

Finexly supports major crypto (BTC, ETH, SOL, and others) alongside fiat in the same endpoint. ExchangeRate-API does not. CurrencyLayer offers a separate CoinLayer product for crypto at additional cost.

Final Verdict

If this comparison came down to a single sentence: ExchangeRate-API wins on annual prepay for non-real-time workloads; CurrencyLayer wins for regulated financial-services customers already locked into APILayer; Finexly wins for everyone else — especially developers who want real-time updates, HTTPS, flexible base currencies, and fair pricing without a year-long commitment.

Ready to test it yourself? Get your free Finexly API key — no credit card required. Start with 1,000 requests per month on the free tier, and upgrade only if you need more. You can also explore our live currency converter to see the rates in action.

Have questions about migrating from ExchangeRate-API or CurrencyLayer to Finexly? The Finexly team offers free migration support for any team moving over 500 requests per day. Reach out via the contact form on finexly.com.