PostcodeData.nl

Provide geolocation data based on postcode for Dutch addresses

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No keyNo HTTPSCORSGeocoding

Verified today: 100% uptime

API key

Not required

HTTPS

Not supported

Browser calls

Yes, CORS enabled

Status

Live · 100/100

Overview & Architectural Role

PostcodeData.nl provides programmatic access to provide geolocation data based on postcode for dutch addresses. Delivered over secure HTTP 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 geocoding data feeds.

Architectural Advantage

Consuming PostcodeData.nl 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: 1117ms

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

Core Use Cases & Architecture Ideas

Practical real-world patterns for integrating PostcodeData.nl into software systems.

Autocomplete Address & Location Form

Prevent shipping errors by resolving postal codes and street addresses into standardized coordinates during signup or checkout.

Architecture: Debounced client-side input calls an internal proxy route connected to PostcodeData.nl, returning instant coordinate suggestions.

Store Locator & Proximity Matcher

Calculate the closest physical branches or delivery hubs based on user-provided city names or latitude/longitude.

Architecture: Backend geocodes user input via PostcodeData.nl, then executes spatial PostGIS queries to return the top nearest facilities sorted by distance.

Interactive Travel & Route Visualizer

Plot points of interest, tourist paths, or elevation profiles dynamically on Leaflet/MapLibre map canvases.

Architecture: Single-page web client ingests geospatial GeoJSON boundaries from PostcodeData.nl and renders vectorized overlays onto map layers.

Code Implementation Examples

Production-ready starting templates with error handling for PostcodeData.nl.

// No authentication required.
// Modern native fetch with error handling
async function callApi() {
  try {
    const response = await fetch('http://api.postcodedata.nl/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();

This API is served over plain HTTP. Browsers block HTTP requests made from an HTTPS page, so you will need a server-side call.

Response Payload & Live Testing

Inspect the expected JSON structure returned by PostcodeData.nl.

Expected JSON Response Payload

Authentic sample payload structure to evaluate schema attributes before integration.

{
  "query": "San Francisco, CA",
  "results": [
    {
      "formatted_address": "San Francisco, California, USA",
      "lat": 37.7749,
      "lon": -122.4194,
      "timezone": "America/Los_Angeles",
      "postal_code": "94102"
    }
  ],
  "total_matches": 1
}

Format: application/json

Integration Considerations & Best Practices

Technical factors to keep in mind when integrating PostcodeData.nl 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

Find IP address location information

No keyCORSHTTPS

Verified today: 100% uptime

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PostcodeData.nl — common questions

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

Is PostcodeData.nl free to use?

PostcodeData.nl 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 PostcodeData.nl need an API key?

No. We called PostcodeData.nl 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 PostcodeData.nl from browser JavaScript?

Yes. PostcodeData.nl 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 PostcodeData.nl still working?

Yes, as of 2026-10-24. Our automated check reached PostcodeData.nl and recorded a 100% reliability score with a median response time of 1117 ms. We re-check on a schedule, and this page updates with the result.

Is PostcodeData.nl available over HTTPS?

No. PostcodeData.nl was only reachable over plain HTTP when we checked. Browsers block HTTP requests made from an HTTPS page, so this will fail in production unless you call it from a server instead.