postalcodes-india v1.0.0

postalcodes-india

A lightweight and efficient Indian postal code lookup library with no external dependencies. Compatible with both Node.js and browser/React environments.

I try my best to monitor the required dependencies daily and publish updates to the npm package whenever changes are detected.

🔄 Data Last Updated: 8th March 2025

Features

• Fast in-memory postal code lookups
• Multiple lookup methods for different use cases
• Find postal codes by place, state, and district
• Find postal codes within a radius of coordinates
• Returns complete information including state, district, sub-district, and coordinates
• TypeScript support with full type definitions
• Zero runtime dependencies
• Universal compatibility: Works in Node.js, browsers, and React applications
• Tree-shakable: Import only what you need

Installation

npm install postalcodes-india

Usage

In Node.js (ESM)

import postalcodes from "postalcodes-india"

// Complete lookup with validity check
const info = postalcodes.find("560029")
console.log(info)

In Node.js (CommonJS)

const postalcodes = require("postalcodes-india")

// Complete lookup with validity check
const info = postalcodes.find("560029")
console.log(info)

In React

import React, { useState } from "react"
import postalcodes from "postalcodes-india"

function PostalCodeLookup() {
  const [code, setCode] = useState("")
  const [result, setResult] = useState(null)

  const handleLookup = () => {
    const info = postalcodes.find(code)
    setResult(info)
  }

  return (
    <div>
      <h2>Postal Code Lookup</h2>
      <input type="text" value={code} onChange={(e) => setCode(e.target.value)} placeholder="Enter postal code" />
      <button onClick={handleLookup}>Lookup</button>

      {result && (
        <div>
          <h3>Results:</h3>
          {result.isValid ? (
            <ul>
              <li>State: {result.state}</li>
              <li>District: {result.district}</li>
              <li>Sub-District: {result.subDistrict}</li>
              <li>Place: {result.place}</li>
              <li>
                Coordinates: {result.latitude}, {result.longitude}
              </li>
            </ul>
          ) : (
            <p>Invalid postal code</p>
          )}
        </div>
      )}
    </div>
  )
}

export default PostalCodeLookup

In Browser (via CDN)

<script src="https://cdn.jsdelivr.net/npm/postalcodes-india/dist/index.umd.js"></script>
<script>
  // The library is available as a global variable 'postalcodes'
  const info = postalcodes.find("110001")
  console.log(info)
</script>

Tree-shaking (Import only what you need)

import { find, findByRadius } from "postalcodes-india"

// Use specific functions without importing the entire library
const info = find("400001")
const nearby = findByRadius(19.076, 72.8777, 5) // 5km radius around Mumbai

Examples

import postalcodes from "postalcodes-india"

// Complete lookup with validity check
const info = postalcodes.find("744301")
console.log(info)
/* Output:
{
  state: 'Andaman & Nicobar Islands',
  stateCode: '01',
  district: 'Nicobar',
  subDistrict: 'Carnicobar',
  place: 'Sawai',
  latitude: 7.5166,
  longitude: 93.6031,
  isValid: true
}
*/

// For invalid postal codes, returns empty values with isValid: false
const invalid = postalcodes.find("000000")
console.log(invalid)
/* Output:
{
  state: '',
  stateCode: '',
  district: '',
  subDistrict: '',
  place: '',
  latitude: 0,
  longitude: 0,
  isValid: false
}
*/

// Get just the state information
const stateInfo = postalcodes.findState("744301")
console.log(stateInfo) // { state: 'Andaman & Nicobar Islands', stateCode: '01', isValid: true }

// Get just the district information
const districtInfo = postalcodes.findDistrict("744301")
console.log(districtInfo) // { district: 'Nicobar', districtCode: '638', state: 'Andaman & Nicobar Islands', stateCode: '01', isValid: true }

// Get just the place
const placeInfo = postalcodes.findPlace("744301")
console.log(placeInfo) // { place: 'Sawai', isValid: true }

// Get just the coordinates
const coords = postalcodes.findCoordinates("744301")
console.log(coords) // { latitude: 7.5166, longitude: 93.6031, isValid: true }

// Get complete location hierarchy
const hierarchy = postalcodes.findHierarchy("744301")
console.log(hierarchy)
/* Output:
{
  state: 'Andaman & Nicobar Islands',
  stateCode: '01',
  district: 'Nicobar',
  districtCode: '638',
  subDistrict: 'Carnicobar',
  place: 'Sawai',
  isValid: true
}
*/

// Find postal codes for a place and state
const placePostals = postalcodes.findByPlace("Sawai", "01")
console.log(`Found ${placePostals.length} postal codes`)

// Find postal codes in a district
const districtPostals = postalcodes.findByDistrict("Nicobar", "01")
console.log(`Nicobar district has ${districtPostals.length} postal codes`)

// Find postal codes within 10 kilometers of coordinates
const nearby = postalcodes.findByRadius(7.5166, 93.6031, 10)
console.log(`Found ${nearby.length} postal codes within 10km radius`)

// Get all states
const states = postalcodes.getStates()
console.log(`India has ${states.length} states and union territories with postal codes`)

API

find(postalCode: string): PostalLookupResult

Returns complete information for a postal code with an isValid flag. Always returns an object, even for invalid postal codes.

interface PostalLookupResult {
  state: string // Full state/UT name
  stateCode: string // State code
  district: string // District name
  subDistrict: string // Sub-district/tehsil name
  place: string // Place name
  latitude: number // Decimal latitude
  longitude: number // Decimal longitude
  isValid: boolean // Whether the postal code exists
}

// Internal PostalCodeInfo interface used by findByPlace, findByDistrict, and findByRadius methods
interface PostalCodeInfo {
  postalCode: string // 6-digit postal code
  placeName: string // Place name
  stateName: string // Full state/UT name
  stateCode: string // State code
  districtName: string // District name
  districtCode: string // District code
  subDistrictName: string // Sub-district name
  latitude: number // Latitude in decimal degrees
  longitude: number // Longitude in decimal degrees
}

findState(postalCode: string): StateResult

Returns state information for a postal code with validity check.

interface StateResult {
  state: string // Full state/UT name
  stateCode: string // State code
  isValid: boolean // Whether the postal code exists
}

findDistrict(postalCode: string): DistrictResult

Returns district information for a postal code with validity check.

interface DistrictResult {
  district: string // District name
  districtCode: string // District code
  state: string // State name
  stateCode: string // State code
  isValid: boolean // Whether the postal code exists
}

findPlace(postalCode: string): { place: string; isValid: boolean }

Returns place name for a postal code with validity check.

findCoordinates(postalCode: string): Coordinates

Returns latitude and longitude for a postal code with validity check.

interface Coordinates {
  latitude: number // Decimal latitude
  longitude: number // Decimal longitude
  isValid: boolean // Whether the postal code exists
}

findHierarchy(postalCode: string): LocationHierarchy

Returns complete location hierarchy for a postal code.

interface LocationHierarchy {
  state: string // State name
  stateCode: string // State code
  district: string // District name
  districtCode: string // District code
  subDistrict: string // Sub-district name
  place: string // Place name
  isValid: boolean // Whether the postal code exists
}

findByPlace(place: string, stateCode: string): PostalCodeInfo[]

Finds all postal codes for a given place and state. Returns an array of PostalCodeInfo objects.

findByDistrict(districtName: string, stateCode: string): PostalCodeInfo[]

Finds all postal codes in a given district. Returns an array of PostalCodeInfo objects.

findByRadius(latitude: number, longitude: number, radiusKm: number): PostalCodeInfo[]

Finds postal codes within a radius of coordinates, sorted by distance. Returns an array of PostalCodeInfo objects.

getStates(): Array<{ code: string, name: string }>

Returns all states and union territories with their codes and names.

Data Source

This package uses GeoNames postal code data (under Creative Commons Attribution 4.0 License).

License

MIT