---
title: "ZIP Code Enrichment API: Add Location Intelligence to Your App in Minutes"
description: "Learn how to use the leeworks.dev ZIP Code Enrichment API to add city, state, timezone, and demographic data to any postal code lookup."
date: "2026-05-24"
author: "leeworks.dev"
tags: ["zip-enrichment", "api", "tutorial"]
---

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# ZIP Code Enrichment API: Add Location Intelligence to Your App in Minutes

Every time a user types their ZIP code, there's a wealth of data waiting to be unlocked — city name, state, county, timezone, latitude, longitude, and more. The **leeworks.dev ZIP Code Enrichment API** makes it trivially easy to retrieve all of that in a single API call.

## What Is a ZIP Code Enrichment API?

A **postal code demographics API** (or ZIP enrichment API) takes a 5-digit US ZIP code as input and returns structured data about that location. This is useful for:

- **E-commerce** — display the user's city/state after they type a ZIP, skip the state dropdown
- **Shipping calculators** — determine timezone and region for delivery estimates  
- **Analytics dashboards** — group customers by region, state, or county
- **Lead scoring** — enrich CRM contacts with location data automatically
- **Form UX** — auto-fill city/state fields for a smoother checkout experience

## Why Build on leeworks.dev?

Unlike scraping Google Maps or paying for expensive enterprise solutions, the leeworks.dev ZIP Enrichment API:

- Returns **sub-50ms responses** (SQLite-backed, no external dependencies)
- Provides **100% US ZIP code coverage** using the free USPS/Census dataset
- Is available on **RapidAPI** with a generous free tier
- Has a **simple, well-documented REST API** following the OpenAPI 3.1 standard

## Quick Start

### 1. Get Your API Key

Sign up on [RapidAPI](https://rapidapi.com/leeworks/api/zip-enrichment) and subscribe to a plan. The Free tier gives you 500 requests/month.

### 2. Make Your First Call

```bash
curl -X GET "https://zip.leeworks.dev/v1/lookup?zip=90210" \
  -H "X-RapidAPI-Key: YOUR_API_KEY" \
  -H "X-RapidAPI-Host: zip.leeworks.dev"
```

### 3. Parse the Response

```json
{
  "zip": "90210",
  "city": "Beverly Hills",
  "state": "CA",
  "state_full": "California",
  "county": "Los Angeles",
  "timezone": "America/Los_Angeles",
  "latitude": 34.0901,
  "longitude": -118.4065,
  "population": 20124
}
```

## Code Examples

### JavaScript / Node.js

```javascript
const response = await fetch('https://zip.leeworks.dev/v1/lookup?zip=10001', {
  headers: {
    'X-RapidAPI-Key': process.env.RAPIDAPI_KEY,
    'X-RapidAPI-Host': 'zip.leeworks.dev',
  },
});
const data = await response.json();
console.log(`${data.city}, ${data.state} (${data.timezone})`);
// → "New York, NY (America/New_York)"
```

### Python

```python
import httpx

resp = httpx.get(
    "https://zip.leeworks.dev/v1/lookup",
    params={"zip": "60601"},
    headers={
        "X-RapidAPI-Key": "YOUR_API_KEY",
        "X-RapidAPI-Host": "zip.leeworks.dev",
    },
)
data = resp.json()
print(f"{data['city']}, {data['state']}")
# → "Chicago, IL"
```

## Pricing

| Plan | Requests/mo | Price | Best for |
|------|------------|-------|---------|
| Free | 500 | $0 | Prototyping |
| Basic | 10,000 | $9/mo | Small apps |
| Pro | 100,000 | $19/mo | Growing products |
| Ultra | 1,000,000 | $49/mo | High volume |

**[Subscribe on RapidAPI →](https://rapidapi.com/leeworks/api/zip-enrichment)**

## Use Case: Auto-fill City/State on Checkout

Here's a complete React component that auto-fills city and state when a user enters their ZIP:

```tsx
import { useState } from 'react';

export function ZipField() {
  const [zip, setZip] = useState('');
  const [location, setLocation] = useState<{ city: string; state: string } | null>(null);

  const handleZipChange = async (e: React.ChangeEvent<HTMLInputElement>) => {
    const value = e.target.value.replace(/\D/g, '').slice(0, 5);
    setZip(value);
    if (value.length === 5) {
      const res = await fetch(`/api/zip-lookup?zip=${value}`);
      if (res.ok) setLocation(await res.json());
    }
  };

  return (
    <div>
      <input value={zip} onChange={handleZipChange} placeholder="ZIP Code" maxLength={5} />
      {location && <p>📍 {location.city}, {location.state}</p>}
    </div>
  );
}
```

## Conclusion

The leeworks.dev **ZIP code enrichment API** is the fastest way to add location intelligence to any application. With a simple GET request, you get city, state, county, timezone, and coordinates — no geocoding, no rate-limit headaches.

**[Get started for free →](https://rapidapi.com/leeworks/api/zip-enrichment)**

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