Zippopotam.us

How to Use This API

1. US Zip Code Lookup — Beverly Hills

https://api.zippopotam.us/us/90210

Returns: {"post code":"90210","country":"United States","places":[{"place name":"Beverly Hills","state":"California","latitude":"34.0901","longitude":"-118.4065"}]}

2. UK Postcode Lookup — London

https://api.zippopotam.us/gb/sw1a1aa

UK postcodes work too. Use country code "gb" and the postcode without spaces.

3. Canadian Postal Code — Toronto

https://api.zippopotam.us/ca/m5v2t6

4. JavaScript — Auto-Fill City & State

async function lookupZip(postalCode, country = 'us') {
  const resp = await fetch(
    `https://api.zippopotam.us/${country}/${postalCode}`
  );
  if (!resp.ok) throw new Error('Postal code not found');
  const data = await resp.json();
  const place = data.places[0];
  return {
    city: place['place name'],
    state: place['state'],
    lat: place['latitude'],
    lng: place['longitude']
  };
}

lookupZip('90210', 'us').then(loc => {
  console.log(`${loc.city}, ${loc.state}`);
  console.log(`GPS: ${loc.lat}, ${loc.lng}`);
});

lookupZip('m5v2t6', 'ca').then(loc => {
  console.log(`Toronto: ${loc.city}, ${loc.state}`);
});

5. Python — Batch Zip Validation

import requests

def validate_zip(postal_code, country='us'):
    resp = requests.get(
        f'https://api.zippopotam.us/{country}/{postal_code}'
    )
    if resp.status_code == 200:
        data = resp.json()
        p = data['places'][0]
        return {
            'valid': True,
            'city': p['place name'],
            'state': p['state'],
            'lat': float(p['latitude']),
            'lng': float(p['longitude'])
        }
    return {'valid': False}

zips = ['10001', '99999', '20500']
for z in zips:
    result = validate_zip(z)
    status = f"{result['city']}, {result['state']}" if result['valid'] else 'Invalid'
    print(f"{z}: {status}")