How to Integrate Address Autocomplete in React, Vue, and Angular

Q: Should I call the Sthan.io API directly from my frontend or use a backend proxy?

For production applications, we strongly recommend using a backend proxy instead of calling the API directly from your frontend. This approach keeps your API key secure, allows you to implement rate limiting and request validation, and gives you better control over API usage. While direct frontend calls work for development and prototyping, exposing your API key in client-side code creates security risks.

Q: Does Sthan.io autocomplete work internationally or just for US addresses?

Sthan.io currently supports USA (full address autocomplete with USPS-verified data) and India (Pincode, City, and Locality autocomplete). For US addresses, you get complete street-level autocomplete with unit numbers and smart abbreviation handling. For Indian addresses, you can autocomplete Pincodes, Cities, and Localities with multiple display options. Additional countries and regions are being evaluated for future expansion.

Q: How do I handle autocomplete for addresses not found in the database?

Always provide a manual entry fallback for addresses that don't appear in autocomplete suggestions. This is especially important for new constructions, rural addresses, or non-standard locations. Display a message like 'Can't find your address? Enter it manually' and allow users to type freely without forcing autocomplete selection. You can also implement address verification on form submission to catch any typos or formatting issues in manually-entered addresses.

Q: What's the difference between autocomplete and address verification?

Address autocomplete helps users type addresses faster by suggesting valid addresses as they type, improving user experience during data entry. Address verification validates and corrects addresses after submission, ensuring the address is deliverable and properly formatted for shipping or mailing. Use autocomplete for better UX during form filling, and verification for data quality assurance before processing orders or sending mail.

Q: Can I filter autocomplete results by country or region?

Yes, the Sthan.io API accepts optional parameters to filter results by country, state, or region. This is particularly useful for applications that only ship to specific areas or need to collect addresses within certain jurisdictions. You can pass these parameters in your API request to limit suggestions to your target geography.

Q: How accurate is the autocomplete data?

Sthan.io maintains a proprietary address database sourced from multiple authoritative government and commercial data providers, with daily updates to reflect new construction, postal changes, and geographic updates. Our database is continuously refreshed to ensure you have access to the most current address information available. This comprehensive approach ensures high accuracy and coverage for addresses across our supported regions.

Q: Can I use this in a form library like React Hook Form or Formik?

Absolutely! The autocomplete components shown in this guide integrate seamlessly with popular form libraries. For React Hook Form, you can use the register function or Controller component to connect our autocomplete to your form state. With Formik, you can use Field component with a custom render function or connect it via setFieldValue. The same patterns work for Angular Reactive Forms (using formControlName) and Vue form libraries.

Introduction

Address autocomplete is a critical feature for modern web applications. Whether you're building an e-commerce checkout, a delivery platform, or a customer registration form, providing real-time address suggestions improves user experience and data accuracy. If you're new to address APIs, check out our Complete Guide to Address Verification APIs.

In this comprehensive guide, you'll learn how to integrate address autocomplete APIs into the three most popular JavaScript frameworks: React, Vue, and Angular. We'll cover:

Complete implementation examples for each framework
Performance optimization with debouncing
Error handling and loading states
TypeScript support
Best practices and production tips

Note: This guide uses the Sthan.io Address Autocomplete API, but the patterns apply to any REST API service. You get 10,000 free autocomplete requests per month with a free account.

Prerequisites

Before we begin, make sure you have:

Node.js (v16 or higher) and npm installed
Basic knowledge of React, Vue, or Angular
A Sthan.io API key (sign up for free)
A backend API endpoint that securely handles Sthan.io authentication and forwards requests
A text editor or IDE (VS Code recommended)

Important Note on Architecture:

This tutorial focuses on frontend implementation using React, Vue, and Angular. For security reasons, you should never call the Sthan.io API directly from your frontend as this would expose your API credentials in the browser.

Recommended Architecture: Frontend → Your Backend → Sthan.io API
The code examples below call a generic backend endpoint (/api/address/autocomplete). Your backend should handle authentication and forward requests to Sthan.io securely.
Read our upcoming Backend Integration Guide for authentication and proxy setup instructions!

Implementation Examples

Choose your framework below to see the complete implementation with code examples. Each implementation follows the same patterns: debouncing, error handling, and keyboard navigation.

React Implementation

Let's build a reusable address autocomplete component in React using React hooks and TypeScript. This component will fetch suggestions as the user types and handle loading states gracefully.

Step 1: Create the Custom Hook

First, we'll create a custom hook to manage the autocomplete logic:

// hooks/useAddressAutocomplete.ts
import { useState, useEffect, useCallback } from 'react';

interface UseAddressAutocompleteResult {
  suggestions: string[];  // Array of address strings
  loading: boolean;
  error: string | null;
  fetchSuggestions: (query: string) => void;
}

export const useAddressAutocomplete = (
  debounceMs: number = 300
): UseAddressAutocompleteResult => {
  const [suggestions, setSuggestions] = useState<string[]>([]);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [query, setQuery] = useState('');

  // Debounced fetch function
  useEffect(() => {
    if (!query || query.length < 3) {
      setSuggestions([]);
      return;
    }

    const timer = setTimeout(async () => {
      setLoading(true);
      setError(null);

      try {
        // Call YOUR backend API endpoint
        const response = await fetch(
          `/api/address/autocomplete?query=${encodeURIComponent(query)}`,
          {
            headers: {
              'Content-Type': 'application/json'
            }
          }
        );

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

        const data = await response.json();

        // Your backend should return: { suggestions: string[] }
        setSuggestions(data.suggestions || []);
      } catch (err) {
        setError(err instanceof Error ? err.message : 'Failed to fetch suggestions');
        setSuggestions([]);
      } finally {
        setLoading(false);
      }
    }, debounceMs);

    return () => clearTimeout(timer);
  }, [query, debounceMs]);

  const fetchSuggestions = useCallback((searchQuery: string) => {
    setQuery(searchQuery);
  }, []);

  return { suggestions, loading, error, fetchSuggestions };
};

Step 2: Create the Autocomplete Component

Now let's build the UI component that uses our custom hook:

// components/AddressAutocomplete.tsx
import React, { useState, useRef, useEffect } from 'react';
import { useAddressAutocomplete } from '../hooks/useAddressAutocomplete';

interface AddressAutocompleteProps {
  onSelect: (address: string) => void;
  placeholder?: string;
}

export const AddressAutocomplete: React.FC<AddressAutocompleteProps> = ({
  onSelect,
  placeholder = 'Start typing an address...'
}) => {
  const [inputValue, setInputValue] = useState('');
  const [showDropdown, setShowDropdown] = useState(false);
  const [selectedIndex, setSelectedIndex] = useState(-1);
  const inputRef = useRef<HTMLInputElement>(null);
  const dropdownRef = useRef<HTMLDivElement>(null);

  const { suggestions, loading, error, fetchSuggestions } = useAddressAutocomplete();

  const handleInputChange = (e: React.ChangeEvent<HTMLInputElement>) => {
    const value = e.target.value;
    setInputValue(value);
    fetchSuggestions(value);
    setShowDropdown(true);
    setSelectedIndex(-1);
  };

  const handleSelect = (suggestion: string) => {
    setInputValue(suggestion);
    setShowDropdown(false);
    onSelect(suggestion);
  };

  const handleKeyDown = (e: React.KeyboardEvent) => {
    if (!showDropdown || suggestions.length === 0) return;

    switch (e.key) {
      case 'ArrowDown':
        e.preventDefault();
        setSelectedIndex(prev =>
          prev < suggestions.length - 1 ? prev + 1 : prev
        );
        break;
      case 'ArrowUp':
        e.preventDefault();
        setSelectedIndex(prev => prev > 0 ? prev - 1 : -1);
        break;
      case 'Enter':
        e.preventDefault();
        if (selectedIndex >= 0) {
          handleSelect(suggestions[selectedIndex]);
        }
        break;
      case 'Escape':
        setShowDropdown(false);
        break;
    }
  };

  // Close dropdown when clicking outside
  useEffect(() => {
    const handleClickOutside = (event: MouseEvent) => {
      if (
        dropdownRef.current &&
        !dropdownRef.current.contains(event.target as Node) &&
        !inputRef.current?.contains(event.target as Node)
      ) {
        setShowDropdown(false);
      }
    };

    document.addEventListener('mousedown', handleClickOutside);
    return () => document.removeEventListener('mousedown', handleClickOutside);
  }, []);

  return (
    <div className="address-autocomplete" style={{ position: 'relative' }}>
      <input
        ref={inputRef}
        type="text"
        value={inputValue}
        onChange={handleInputChange}
        onKeyDown={handleKeyDown}
        onFocus={() => suggestions.length > 0 && setShowDropdown(true)}
        placeholder={placeholder}
        className="form-control"
        aria-label="Address input"
        aria-autocomplete="list"
        aria-expanded={showDropdown}
      />

      {loading && (
        <div className="position-absolute end-0 top-50 translate-middle-y me-3">
          <div className="spinner-border spinner-border-sm" role="status">
            <span className="visually-hidden">Loading...</span>
          </div>
        </div>
      )}

      {showDropdown && !loading && suggestions.length > 0 && (
        <div
          ref={dropdownRef}
          className="dropdown-menu show w-100"
          style={{
            maxHeight: '300px',
            overflowY: 'auto',
            position: 'absolute',
            zIndex: 1000
          }}
        >
          {suggestions.map((suggestion, index) => (
            <button
              key={index}
              className={`dropdown-item ${index === selectedIndex ? 'active' : ''}`}
              onClick={() => handleSelect(suggestion)}
              type="button"
            >
              {suggestion}
            </button>
          ))}
        </div>
      )}

      {error && (
        <div className="text-danger small mt-1">
          <i className="fas fa-exclamation-circle me-1" aria-hidden="true"></i>
          {error}
        </div>
      )}
    </div>
  );
};

Step 3: Usage Example

// App.tsx
import { AddressAutocomplete } from './components/AddressAutocomplete';

function App() {
  const handleAddressSelect = (address: string) => {
    console.log('Selected address:', address);
    // Handle the selected address (e.g., save to form state)
  };

  return (
    <div className="container mt-5">
      <h2>Shipping Address</h2>
      <AddressAutocomplete
        onSelect={handleAddressSelect}
        placeholder="Enter your shipping address"
      />
    </div>
  );
}

Vue 3 Implementation

Now let's implement the same functionality in Vue 3 using the Composition API and TypeScript. This approach provides excellent reactivity and reusability.

Step 1: Create the Composable

// composables/useAddressAutocomplete.ts
import { ref, watch } from 'vue';

export function useAddressAutocomplete(debounceMs: number = 300) {
  const suggestions = ref<string[]>([]);  // Array of address strings
  const loading = ref(false);
  const error = ref<string | null>(null);
  const query = ref('');
  let timeoutId: number | null = null;

  const fetchSuggestions = async (searchQuery: string) => {
    query.value = searchQuery;

    if (!searchQuery || searchQuery.length < 3) {
      suggestions.value = [];
      return;
    }

    // Clear previous timeout
    if (timeoutId) {
      clearTimeout(timeoutId);
    }

    // Debounce the API call
    timeoutId = window.setTimeout(async () => {
      loading.value = true;
      error.value = null;

      try {
        // Call YOUR backend API endpoint
        const response = await fetch(
          `/api/address/autocomplete?query=${encodeURIComponent(searchQuery)}`,
          {
            headers: {
              'Content-Type': 'application/json'
            }
          }
        );

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

        const data = await response.json();

        // Your backend should return: { suggestions: string[] }
        suggestions.value = data.suggestions || [];
      } catch (err) {
        error.value = err instanceof Error ? err.message : 'Failed to fetch suggestions';
        suggestions.value = [];
      } finally {
        loading.value = false;
      }
    }, debounceMs);
  };

  return {
    suggestions,
    loading,
    error,
    fetchSuggestions
  };
}

Step 2: Create the Component

<!-- components/AddressAutocomplete.vue -->
<template>
  <div class="address-autocomplete" style="position: relative">
    <input
      v-model="inputValue"
      @input="handleInput"
      @keydown="handleKeyDown"
      @focus="handleFocus"
      type="text"
      :placeholder="placeholder"
      class="form-control"
      aria-label="Address input"
      aria-autocomplete="list"
      :aria-expanded="showDropdown"
    />

    <div
      v-if="loading"
      class="position-absolute end-0 top-50 translate-middle-y me-3"
    >
      <div class="spinner-border spinner-border-sm" role="status">
        <span class="visually-hidden">Loading...</span>
      </div>
    </div>

    <div
      v-if="showDropdown && !loading && suggestions.length > 0"
      ref="dropdownRef"
      class="dropdown-menu show w-100"
      style="max-height: 300px; overflow-y: auto; position: absolute; z-index: 1000"
    >
      <button
        v-for="(suggestion, index) in suggestions"
        :key="index"
        :class="['dropdown-item', { active: index === selectedIndex }]"
        @click="handleSelect(suggestion)"
        type="button"
      >
        {{ suggestion }}
      </button>
    </div>

    <div v-if="error" class="text-danger small mt-1">
      <i class="fas fa-exclamation-circle me-1" aria-hidden="true"></i>
      {{ error }}
    </div>
  </div>
</template>

<script setup lang="ts">
import { ref, onMounted, onUnmounted } from 'vue';
import { useAddressAutocomplete } from '../composables/useAddressAutocomplete';

interface Props {
  placeholder?: string;
}

interface Emits {
  (e: 'select', address: string): void;
}

const props = withDefaults(defineProps<Props>(), {
  placeholder: 'Start typing an address...'
});

const emit = defineEmits<Emits>();

const inputValue = ref('');
const showDropdown = ref(false);
const selectedIndex = ref(-1);
const dropdownRef = ref<HTMLElement | null>(null);

const { suggestions, loading, error, fetchSuggestions } = useAddressAutocomplete();

const handleInput = (event: Event) => {
  const target = event.target as HTMLInputElement;
  fetchSuggestions(target.value);
  showDropdown.value = true;
  selectedIndex.value = -1;
};

const handleSelect = (suggestion: string) => {
  inputValue.value = suggestion;
  showDropdown.value = false;
  emit('select', suggestion);
};

const handleKeyDown = (event: KeyboardEvent) => {
  if (!showDropdown.value || suggestions.value.length === 0) return;

  switch (event.key) {
    case 'ArrowDown':
      event.preventDefault();
      selectedIndex.value =
        selectedIndex.value < suggestions.value.length - 1
          ? selectedIndex.value + 1
          : selectedIndex.value;
      break;
    case 'ArrowUp':
      event.preventDefault();
      selectedIndex.value = selectedIndex.value > 0 ? selectedIndex.value - 1 : -1;
      break;
    case 'Enter':
      event.preventDefault();
      if (selectedIndex.value >= 0) {
        handleSelect(suggestions.value[selectedIndex.value]);
      }
      break;
    case 'Escape':
      showDropdown.value = false;
      break;
  }
};

const handleFocus = () => {
  if (suggestions.value.length > 0) {
    showDropdown.value = true;
  }
};

// Close dropdown on outside click
const handleClickOutside = (event: MouseEvent) => {
  if (dropdownRef.value && !dropdownRef.value.contains(event.target as Node)) {
    showDropdown.value = false;
  }
};

onMounted(() => {
  document.addEventListener('mousedown', handleClickOutside);
});

onUnmounted(() => {
  document.removeEventListener('mousedown', handleClickOutside);
});
</script>

Step 3: Usage Example

<!-- App.vue -->
<template>
  <div class="container mt-5">
    <h2>Shipping Address</h2>
    <AddressAutocomplete
      placeholder="Enter your shipping address"
      @select="handleAddressSelect"
    />
  </div>
</template>

<script setup lang="ts">
import AddressAutocomplete from './components/AddressAutocomplete.vue';

const handleAddressSelect = (address: string) => {
  console.log('Selected address:', address);
  // Handle the selected address (e.g., save to form state)
};
</script>

Angular Implementation

Finally, let's implement address autocomplete in Angular using services, RxJS operators, and TypeScript. Angular's powerful dependency injection makes this implementation very maintainable.

Step 1: Create the Service

// services/address-autocomplete.service.ts
import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';
import { Observable, of } from 'rxjs';
import { map, catchError, debounceTime, distinctUntilChanged, switchMap } from 'rxjs/operators';

@Injectable({
  providedIn: 'root'
})
export class AddressAutocompleteService {
  // Call YOUR backend API endpoint
  private readonly apiUrl = '/api/address/autocomplete';

  constructor(private http: HttpClient) {}

  searchAddresses(query: string): Observable<string[]> {
    if (!query || query.length < 3) {
      return of([]);
    }

    const params = { query: query };

    // Your backend handles authentication
    return this.http.get<any>(this.apiUrl, { params }).pipe(
      map(response => response.suggestions || []),
      catchError(error => {
        console.error('Address autocomplete error:', error);
        return of([]);
      })
    );
  }
}

Step 2: Create the Component

// components/address-autocomplete/address-autocomplete.component.ts
import { Component, EventEmitter, Input, Output, OnInit, OnDestroy } from '@angular/core';
import { FormControl } from '@angular/forms';
import { Subject, Subscription } from 'rxjs';
import { debounceTime, distinctUntilChanged, switchMap, tap } from 'rxjs/operators';
import { AddressAutocompleteService } from '../../services/address-autocomplete.service';

@Component({
  selector: 'app-address-autocomplete',
  templateUrl: './address-autocomplete.component.html',
  styleUrls: ['./address-autocomplete.component.css']
})
export class AddressAutocompleteComponent implements OnInit, OnDestroy {
  @Input() placeholder: string = 'Start typing an address...';
  @Input() debounceMs: number = 300;
  @Output() select = new EventEmitter<string>();

  searchControl = new FormControl('');
  suggestions: string[] = [];
  loading = false;
  showDropdown = false;
  selectedIndex = -1;

  private subscription?: Subscription;

  constructor(private addressService: AddressAutocompleteService) {}

  ngOnInit(): void {
    this.subscription = this.searchControl.valueChanges.pipe(
      tap(() => {
        this.loading = true;
        this.showDropdown = true;
        this.selectedIndex = -1;
      }),
      debounceTime(this.debounceMs),
      distinctUntilChanged(),
      switchMap(query => this.addressService.searchAddresses(query || '')),
      tap(() => this.loading = false)
    ).subscribe(suggestions => {
      this.suggestions = suggestions;
    });
  }

  ngOnDestroy(): void {
    this.subscription?.unsubscribe();
  }

  onSelectSuggestion(suggestion: string): void {
    this.searchControl.setValue(suggestion);
    this.showDropdown = false;
    this.select.emit(suggestion);
  }

  onKeyDown(event: KeyboardEvent): void {
    if (!this.showDropdown || this.suggestions.length === 0) return;

    switch (event.key) {
      case 'ArrowDown':
        event.preventDefault();
        this.selectedIndex = this.selectedIndex < this.suggestions.length - 1
          ? this.selectedIndex + 1
          : this.selectedIndex;
        break;
      case 'ArrowUp':
        event.preventDefault();
        this.selectedIndex = this.selectedIndex > 0 ? this.selectedIndex - 1 : -1;
        break;
      case 'Enter':
        event.preventDefault();
        if (this.selectedIndex >= 0) {
          this.onSelectSuggestion(this.suggestions[this.selectedIndex]);
        }
        break;
      case 'Escape':
        this.showDropdown = false;
        break;
    }
  }

  onFocus(): void {
    if (this.suggestions.length > 0) {
      this.showDropdown = true;
    }
  }

  onBlur(): void {
    // Delay to allow click on dropdown item
    setTimeout(() => this.showDropdown = false, 200);
  }
}

Step 3: Component Template

<!-- address-autocomplete.component.html -->
<div class="address-autocomplete" style="position: relative">
  <input
    [formControl]="searchControl"
    (keydown)="onKeyDown($event)"
    (focus)="onFocus()"
    (blur)="onBlur()"
    type="text"
    [placeholder]="placeholder"
    class="form-control"
    aria-label="Address input"
    aria-autocomplete="list"
    [attr.aria-expanded]="showDropdown"
  />

  <div *ngIf="loading" class="position-absolute end-0 top-50 translate-middle-y me-3">
    <div class="spinner-border spinner-border-sm" role="status">
      <span class="visually-hidden">Loading...</span>
    </div>
  </div>

  <div
    *ngIf="showDropdown && !loading && suggestions.length > 0"
    class="dropdown-menu show w-100"
    style="max-height: 300px; overflow-y: auto; position: absolute; z-index: 1000"
  >
    <button
      *ngFor="let suggestion of suggestions; let i = index"
      [class.active]="i === selectedIndex"
      (click)="onSelectSuggestion(suggestion)"
      class="dropdown-item"
      type="button"
    >
      {{ suggestion }}
    </button>
  </div>
</div>

Step 4: Usage Example

// app.component.ts
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  template: `
    <div class="container mt-5">
      <h2>Shipping Address</h2>
      <app-address-autocomplete
        placeholder="Enter your shipping address"
        (select)="onAddressSelect($event)"
      ></app-address-autocomplete>
    </div>
  `
})
export class AppComponent {
  onAddressSelect(address: string): void {
    console.log('Selected address:', address);
    // Handle the selected address
  }
}

Step 5: Module Configuration

// app.module.ts
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { HttpClientModule } from '@angular/common/http';
import { ReactiveFormsModule } from '@angular/forms';
import { AppComponent } from './app.component';
import { AddressAutocompleteComponent } from './components/address-autocomplete/address-autocomplete.component';

@NgModule({
  declarations: [
    AppComponent,
    AddressAutocompleteComponent
  ],
  imports: [
    BrowserModule,
    HttpClientModule,
    ReactiveFormsModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

Performance Optimizations

What's Included: The code examples above already include several performance optimizations out of the box!

1. Debouncing (Already Implemented)

All three implementations include debouncing (300ms default) to prevent excessive API calls as users type. This significantly reduces API usage and improves performance. You can adjust this value by passing a different debounceMs parameter. Check our rate limiting documentation for more optimization tips.

2. Minimum Query Length (Already Implemented)

We only trigger searches when the query is at least 3 characters long. This prevents useless API calls for very short queries that would return too many results. The examples check query.length < 3 before making any requests.

3. Request Cancellation (Angular Only)

Angular's implementation uses RxJS switchMap which automatically cancels pending requests when new ones are initiated. For React/Vue, you can add this optimization using AbortController:

// React/Vue: Add request cancellation
const abortController = new AbortController();

fetch(url, { signal: abortController.signal })
  .then(response => response.json())
  .catch(err => {
    if (err.name === 'AbortError') {
      // Request was cancelled, ignore
      return;
    }
    throw err;
  });

// Cancel previous request when new one starts
abortController.abort();

Pro Tip: Adjust the debounce timeout based on your API's response time. Faster APIs can use 200ms, slower ones might need 400-500ms.

4. Additional: Client-Side Caching

Optional enhancement: Consider adding client-side caching for repeated queries to further reduce API calls:

// Simple cache example
const cache = new Map<string, string[]>();

const getCachedOrFetch = async (query: string) => {
  if (cache.has(query)) {
    return cache.get(query);
  }

  const results = await fetchFromAPI(query);
  cache.set(query, results);
  return results;
};

Best Practices

Security

Never expose API keys in frontend code - Use environment variables and proxy requests through your backend. Learn more in our API security documentation
Implement rate limiting on your server to prevent API abuse
Validate and sanitize all address data before storing

Accessibility

Use proper ARIA attributes (aria-label, aria-autocomplete, aria-expanded) following WCAG 2.1 guidelines
Support keyboard navigation (Arrow keys, Enter, Escape)
Provide loading states and error messages
Ensure sufficient color contrast for dropdown items

User Experience

Show loading indicators during API requests
Display helpful error messages when requests fail
Highlight the selected item in the dropdown
Close dropdown on outside click or Escape key
Allow users to type freely without forcing autocomplete selection

Error Handling

Handle network failures gracefully
Provide fallback behavior when API is unavailable
Log errors for debugging without exposing sensitive information to users
Consider implementing retry logic for transient failures

Testing Your Implementation

Here are some key test scenarios to cover:

Functional Tests

Test typing and receiving suggestions
Test selecting a suggestion updates the input
Test keyboard navigation (up/down arrows, enter, escape)
Test dropdown closes on outside click
Test minimum query length requirement

Edge Cases

Empty results from API
API errors and network failures
Very long addresses
Special characters in addresses
Rapid typing and debouncing behavior

Conclusion

You now have complete, production-ready address autocomplete implementations for React, Vue, and Angular. Each implementation follows framework best practices and includes:

✅ TypeScript support for type safety
✅ Debouncing for performance optimization
✅ Keyboard navigation support
✅ Loading states and error handling
✅ Accessibility features
✅ Responsive design with Bootstrap

The patterns shown here can be adapted to any address autocomplete API, not just Sthan.io. Feel free to customize the styling, add additional features, or integrate with your existing form libraries.

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Frequently Asked Questions

For production applications, we strongly recommend using a backend proxy instead of calling the API directly from your frontend. This approach keeps your API key secure, allows you to implement rate limiting and request validation, and gives you better control over API usage. While direct frontend calls work for development and prototyping, exposing your API key in client-side code creates security risks. As mentioned in the Architecture & Security note above, your backend should handle authentication and forward requests to the Sthan.io API securely.

Sthan.io currently supports USA (full address autocomplete with USPS-verified data) and India (Pincode, City, and Locality autocomplete). For US addresses, you get complete street-level autocomplete with unit numbers and smart abbreviation handling. For Indian addresses, you can autocomplete Pincodes, Cities, and Localities with multiple display options. Additional countries and regions are being evaluated for future expansion. Check our products page for the latest coverage.

Always provide a manual entry fallback for addresses that don't appear in autocomplete suggestions. This is especially important for new constructions, rural addresses, or non-standard locations. Display a message like "Can't find your address? Enter it manually" and allow users to type freely without forcing autocomplete selection. You can also implement address verification on form submission to catch any typos or formatting issues in manually-entered addresses.

Address autocomplete helps users type addresses faster by suggesting valid addresses as they type, improving user experience during data entry. Address verification validates and corrects addresses after submission, ensuring the address is deliverable and properly formatted for shipping or mailing. Use autocomplete for better UX during form filling, and verification for data quality assurance before processing orders or sending mail. For a comprehensive overview of address verification APIs, check out our Complete Guide to Address Verification APIs.

Yes, the Sthan.io API accepts optional parameters to filter results by country, state, or region. This is particularly useful for applications that only ship to specific areas or need to collect addresses within certain jurisdictions. You can pass these parameters in your API request to limit suggestions to your target geography. Check our API documentation for the complete list of available filtering parameters and usage examples.

Sthan.io maintains a proprietary address database sourced from multiple authoritative government and commercial data providers, with daily updates to reflect new construction, postal changes, and geographic updates. Our database is continuously refreshed to ensure you have access to the most current address information available. This comprehensive approach ensures high accuracy and coverage for addresses across our supported regions.

Absolutely! The autocomplete components shown in this guide integrate seamlessly with popular form libraries. For React Hook Form, you can use the register function or Controller component to connect our autocomplete to your form state. With Formik, you can use Field component with a custom render function or connect it via setFieldValue. The same patterns work for Angular Reactive Forms (using formControlName) and Vue form libraries. The key is treating the autocomplete as a controlled component that updates your form's state.

Introduction

Prerequisites

Implementation Examples

React Implementation

Step 1: Create the Custom Hook

Step 2: Create the Autocomplete Component

Step 3: Usage Example

Vue 3 Implementation

Step 1: Create the Composable

Step 2: Create the Component

Step 3: Usage Example

Angular Implementation

Step 1: Create the Service

Step 2: Create the Component

Step 3: Component Template

Step 4: Usage Example

Step 5: Module Configuration

Performance Optimizations

1. Debouncing (Already Implemented)

2. Minimum Query Length (Already Implemented)

3. Request Cancellation (Angular Only)

4. Additional: Client-Side Caching

Best Practices

Security

Accessibility

User Experience

Error Handling

Testing Your Implementation

Functional Tests

Edge Cases

Conclusion

Ready to Get Started?

Frequently Asked Questions

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