Frankfurter

Exchange rates, currency conversion and time series

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No keyHTTPSCORSCurrency Exchange

Verified today: 100% uptime

API key

Not required

HTTPS

Supported

Browser calls

Yes, CORS enabled

Status

Live · 100/100

Overview & Architectural Role

Frankfurter provides programmatic access to exchange rates, currency conversion and time series. Delivered over secure HTTPS protocols, it exposes structured endpoints designed to integrate cleanly into modern frontend frameworks, backend microservices, and automated data pipelines without requiring local database provisioning.

Who it is built for

Engineers building web dashboards, mobile applications, CLI utilities, or background cron workers in need of reliable currency exchange data feeds.

Architectural Advantage

Consuming Frankfurter removes the operational overhead of running custom scrapers, orchestrating headless browser fleets, or manually seeding and maintaining a local database. Instead of reverse-engineering volatile DOM layouts or dealing with anti-bot IP blocks, your application connects directly to a standardized JSON interface that supports client-side browser execution out of the box. Zero-authentication access allows rapid prototyping and zero-credential static deployments.

What our checks found

Health score: 100/100
Reliability: 100%
Average latency: 3106ms

Last checked 2026-10-24. Measured independently, not self-reported by the provider.

Core Use Cases & Architecture Ideas

Practical real-world patterns for integrating Frankfurter into software systems.

Real-Time Portfolio Valuation Daemon

Recalculate user asset balances and currency conversions continuously against live market exchange rates.

Architecture: A background Redis worker polls Frankfurter on interval, writes normalised price snapshots to a key-value store, and streams updates over WebSockets.

Volatility Alert & Webhook Dispatcher

Notify trading desks or personal subscribers when a target metric swings beyond predefined percentage thresholds.

Architecture: Serverless AWS Lambda or Cloudflare Worker fetches current tick data, compares against moving averages in PostgreSQL, and dispatches Discord/Telegram alerts.

E-Commerce Multi-Currency Checkout

Display localized product prices in international currencies during user cart evaluation.

Architecture: API route caches currency ratios in-memory for 1 hour to minimize latency while guaranteeing accurate transaction rates at payment gateway.

Code Implementation Examples

Production-ready starting templates with error handling for Frankfurter.

// No authentication required.
// Modern native fetch with error handling
async function callApi() {
  try {
    const response = await fetch('https://www.frankfurter.app/api/v1/resource', {
      method: 'GET',
    headers: { Accept: 'application/json' },
    });

    if (!response.ok) {
      throw new Error(`HTTP ${response.status}: ${response.statusText}`);
    }

    const data = await response.json();
    console.log('Response payload:', data);
    return data;
  } catch (error) {
    console.error('API request failed:', error);
    throw error;
  }
}

// callApi();

Response Payload & Live Testing

Inspect the expected JSON structure returned by Frankfurter or execute a real-time live probe directly in your browser.

Expected JSON Response Payload

Authentic sample payload structure to evaluate schema attributes before integration.

{
  "base": "USD",
  "date": "2026-10-24",
  "rates": {
    "EUR": 0.92,
    "GBP": 0.79,
    "JPY": 154.2,
    "CAD": 1.38
  },
  "success": true
}

Format: application/json✓ CORS verified: Safe for direct browser calls

Integration Considerations & Best Practices

Technical factors to keep in mind when integrating Frankfurter into production environments.

Implement In-Memory or Edge Caching

Avoid triggering rate limits on public feeds by caching response payloads in Redis, Vercel KV, or standard HTTP Cache-Control headers with a 5-to-15 minute TTL.

Zero-Credential Environment Protection

While no API key is required, public keyless pools often share global rate limits. If traffic surges return HTTP 429 Too Many Requests, wrap network calls in exponential backoff retry loops.

Direct Client-Side Browser Support

CORS headers are validated and present on responses. You can safely call this endpoint directly from frontend React, Vue, or static HTML pages without an intermediary proxy server.

Validate HTTP Status Before Parsing JSON

Always inspect response.ok before executing response.json(). Upstream services returning 4xx or 502 Bad Gateway often serve HTML error pages, which cause syntax errors when parsed as JSON.

Where this listing comes from

Portuguese free currency prices and conversion with no rate limits

No keyHTTPS

Verified today: 100% uptime

View Details

Frankfurter — common questions

Answered from what our own scheduled checks found, not from the provider's marketing.

Is Frankfurter free to use?

Frankfurter is listed in our free catalogue and required no credential when we called it. It needs no authentication at all, so you can send a request without signing up. Free tiers can still carry rate limits or non-commercial terms, so check the provider's own terms before shipping.

Does Frankfurter need an API key?

No. We called Frankfurter on 2026-10-24 with no key, no token and no Authorization header, and it responded. That is what puts it in our no-key collection.

Can I call Frankfurter from browser JavaScript?

Yes. Frankfurter returned CORS headers when we checked it, so a browser will let your page read the response. You can fetch it directly from client-side JavaScript with no proxy and no backend.

Is Frankfurter still working?

Yes, as of 2026-10-24. Our automated check reached Frankfurter and recorded a 100% reliability score with a median response time of 3106 ms. We re-check on a schedule, and this page updates with the result.

Is Frankfurter available over HTTPS?

Yes. Frankfurter serves over HTTPS, so you can call it from a secure page without triggering a mixed-content block.