AllRatesToday vs Fixer.io vs XE.com vs ExchangeRate-API: The 2026 Exchange Rate API Comparison

Choosing an exchange rate API is a boring decision with expensive consequences. Pick one with stale data and your checkout shows prices 2% off the market. Pick one with a tight free tier and you hit a wall the day you launch. Pick one with EUR-only base currencies and you spend the next sprint rewriting conversion logic.

This article compares the four most-searched exchange rate APIs of 2026 — AllRatesToday, Fixer.io, XE.com, and ExchangeRate-API — across the criteria that actually matter: update frequency, latency, HTTPS, currency coverage, historical data, CORS, and free-tier limits.

TL;DR — Quick Comparison Table

Real-Time Updates: How Fresh Is the Data?

Update frequency is the first question to ask about any exchange rate API, because it determines whether the data is usable for real-money decisions.

• AllRatesToday refreshes every 60 seconds from institutional foreign exchange market data.
• XE.com also runs 60-second updates, backed by 30+ years of FX aggregation.
• Fixer.io updates hourly on most tiers, sourced from the European Central Bank.
• ExchangeRate-API updates daily on the free plan.

For trading, payments, or any flow where the rate affects the amount charged, hourly or daily updates are not enough. During volatile sessions, a major pair can move 1% in minutes — and that gap comes out of your margin or your customer's pocket.

Latency: How Fast Does the API Respond?

• ExchangeRate-API ~134ms — fastest overall, thanks to aggressive CDN caching of daily snapshots.
• AllRatesToday ~214ms — fastest among real-time providers.
• Fixer.io ~342ms.
• XE.com ~471ms — slowest in the group.

ExchangeRate-API wins on raw speed, but it's apples-to-oranges: cached daily data will always respond faster than live data. Among APIs serving real-time rates, AllRatesToday is the fastest by a clear margin.

HTTPS and Security

HTTPS should be table stakes in 2026. It isn't, quite.

• AllRatesToday, XE, ExchangeRate-API — HTTPS on every plan.
• Fixer.io — HTTP-only on the free tier. HTTPS is a paid feature.

If you're on Fixer's free plan and your app runs on HTTPS (which it should), you'll hit mixed-content errors the moment you try to fetch rates from the browser. You'll either pay to upgrade or proxy requests through your backend.

Currency Coverage

• Fixer, XE: 170+ currencies.
• AllRatesToday: 160+ currencies plus precious metals.
• ExchangeRate-API: 160+ currencies.

Coverage differences are marginal unless you need exotic pairs or crypto. For everyday FX (USD, EUR, GBP, JPY, major emerging markets), all four are equivalent.

Base Currency Flexibility

This is where Fixer.io falls apart for non-European use cases.

• AllRatesToday, XE, ExchangeRate-API — any base currency on any plan.
• Fixer.io — EUR only on the free tier. Switching base currency is a paid feature.

If you're building a US, Asian, or LATAM product, Fixer's free tier forces you to fetch EUR-based rates and do the cross-rate math in application code. It works, but it's an unnecessary source of rounding bugs.

Historical Rates

Historical rates are needed for accounting, tax reporting, backtesting, and trend analysis.

• AllRatesToday — included on every paid plan, from €4.99/month.
• Fixer, XE, ExchangeRate-API — paid plans only.

No provider here includes historical data on its free tier. The difference is the entry price: AllRatesToday includes it from €4.99/month, while the others typically start at $10–$15/month. If you're building a dashboard, a monthly P&L converter, or anything that touches past rates, that's a real cost difference.

CORS Support

If you're calling the API directly from the browser — landing pages, SPAs without a backend, embedded widgets — CORS support matters.

• ExchangeRate-API — CORS enabled.
• AllRatesToday — keyless endpoints (official central-bank rates, IP-to-currency, symbols) and the embeddable widget work in the browser. The keyed live-rate API is meant to be called from your server, so your key stays private.
• Fixer, XE — no CORS. Browser calls fail without a proxy.

XE and Fixer assume a server-side integration. For static sites and Jamstack projects, AllRatesToday gives you keyless official rates and a widget in the browser, and live market rates through one small serverless function that holds your key.

Uptime SLA

All four providers publish 99.9%+ SLAs. 99.95% vs 99.9% is 4 hours of extra uptime per year on paper. In practice, real outages usually beat the SLA numbers anyway, and what matters more is how the provider handles incidents — status page, postmortems, response times. Check status page history rather than the marketing-page SLA.

Free Tier: What You Actually Get

• AllRatesToday — Free tier, no card. Real-time 60-second rates, any base currency, HTTPS. Personal and non-commercial use; historical data needs a paid plan.
• ExchangeRate-API — free forever. 1,500 requests/month, daily updates, no historical on free.
• Fixer.io — free but constrained. 100 requests/month, hourly updates, EUR base only, HTTP only.
• XE.com — trial only. Permanent use requires a paid annual plan.

ExchangeRate-API wins on raw request quota (1,500/mo, daily snapshots). AllRatesToday's free tier is a one-time evaluation allowance: enough to test real-time rates and flexible base currencies, but production use means a paid plan from €4.99/month.

When to Use Each API

Use AllRatesToday when

• You need real-time rates at a low entry price (from €4.99/month).
• You need historical data without paying $10+/month.
• You want keyless official rates in the browser, with live rates served through your own backend.
• You want flexible base currencies.

Use ExchangeRate-API when

• Daily rates are good enough.
• You need high request volume on the free tier.
• You want the fastest response times.

Use Fixer.io when

• You're a European product and EUR-base is natural.
• You need ECB-aligned data for regulatory reasons.
• You're already on a paid plan and the ecosystem fits.

Use XE.com when

• You're an enterprise with an annual budget.
• You need XE's brand recognition or ERP integrations (SAP, Oracle, MS Dynamics).
• Multi-asset coverage (FX + metals + select crypto) matters.

The Bottom Line

For most developers in 2026, AllRatesToday is the best default:

• Real-time rates (60-second updates from institutional foreign exchange market data).
• Historical data on every paid plan from €4.99/month.
• Any base currency and HTTPS; keyless endpoints for the browser, keyed API on your server.
• 99.9% uptime and sub-250ms latency.

Fixer remains viable if you're already in its ecosystem. XE is for enterprises with budgets. ExchangeRate-API is the right call when you only need daily rates and want the highest free quota.

FAQ

Which exchange rate API is the most accurate?

Accuracy tracks the data source. Providers using institutional FX market data (AllRatesToday, XE) deliver tighter mid-market rates than providers using ECB end-of-day snapshots (Fixer, ExchangeRate-API on the free tier).

Which exchange rate API has the best free tier?

Depends on the axis. ExchangeRate-API has the highest request cap (1,500/month, renewing monthly). AllRatesToday gives a free tier for evaluation and personal projects, with real-time 60-second rates, any base currency, and HTTPS; historical data and commercial use need a paid plan.

Can I use these APIs from the browser?

ExchangeRate-API supports CORS out of the box. AllRatesToday's keyless endpoints (official rates, IP-to-currency, symbols) allow browser calls; its keyed API is meant to be called from your server so your key stays private. Fixer and XE do not support CORS — you'll need a server-side proxy.

Do these APIs support cryptocurrency?

XE covers select cryptocurrencies. The other three are fiat-focused. For crypto-heavy use cases, consider a dedicated crypto API.

Which API is cheapest for historical rates?

AllRatesToday. Historical rates are included on every paid plan from €4.99/month, the lowest entry price in this comparison. No provider here includes historical data on its free tier.

npm install @allratestoday/sdk