SLF Geocoding API

Overview

SLF, established in 2004, offers a suite of Geocoding APIs specifically designed for the Japanese market. These APIs provide functionalities for address validation, forward geocoding (converting addresses to geographic coordinates), and reverse geocoding (converting coordinates to addresses) with a focus on Japanese location data. The service targets developers and organizations that require high precision and granular detail for addresses within Japan, such as logistics companies, e-commerce platforms, and civic data projects.

The core products include the Geocoding API, Address Search API, and Reverse Geocoding API. The Geocoding API converts textual addresses into latitude and longitude coordinates, accommodating various Japanese address formats. The Address Search API allows users to search for addresses based on partial inputs, facilitating auto-completion and correction features in applications. Conversely, the Reverse Geocoding API translates geographical coordinates back into human-readable Japanese addresses, including administrative divisions and postal codes.

SLF's offerings are distinguished by their specialization in Japanese address data, which often presents unique challenges due to its hierarchical structure and various naming conventions. While global geocoding services like Google Maps Platform provide broad geographic coverage, SLF aims for optimized accuracy and completeness specifically for the Japanese context. This focus can result in more precise matches and fewer ambiguities when dealing with the intricacies of Japanese addresses, such as prefectures, municipalities, and specific building numbers. The API is delivered via standard RESTful endpoints, making it compatible with a wide range of programming environments. Documentation is primarily in Japanese, reflecting its target audience and specialized regional focus on Japanese address data.

For organizations operating within Japan or managing Japanese customer data, the SLF Geocoding API can be a critical tool for ensuring data integrity, improving delivery efficiency, and enhancing location-based services. Its high precision for Japanese addresses makes it suitable for applications requiring accurate mapping, route optimization, demographic analysis, and fraud detection based on location. The API's straightforward integration process, utilizing common web standards, supports efficient development workflows for technical teams.

Key features

• Geocoding API: Converts Japanese addresses into latitude and longitude coordinates with high precision for regional specificities.
• Address Search API: Provides capabilities to search and auto-complete Japanese addresses, supporting partial inputs and fuzzy matching for user-friendly interfaces.
• Reverse Geocoding API: Translates geographic coordinates (latitude and longitude) back into detailed Japanese addresses, including administrative divisions.
• Address Validation: Verifies the existence and correctness of Japanese addresses against a comprehensive database.
• Postal Code Lookup: Facilitates searching for addresses based on Japanese postal codes and vice versa.
• RESTful Interface: Utilizes standard REST API calls for integration into various programming languages and platforms.
• Japanese Data Optimization: Specialized algorithms and datasets for handling the unique complexities and formats of Japanese addresses.

Pricing

SLF's Geocoding API pricing is structured into several tiers, primarily based on the number of requests per month. As of 2026-05-28, the following plans are available:

Detailed pricing information, including terms for enterprise solutions and specific usage scenarios, is available on the SLF Geocoding API pricing page.

Common integrations

SLF's Geocoding API can be integrated into various applications and systems that require precise Japanese location data. While SLF does not provide specific integration guides for third-party platforms, its RESTful API design allows for flexible integration:

• Web and Mobile Applications: Integrate geocoding and address search functionalities into customer-facing applications for form auto-completion, location-based services, or mapping features.
• CRM and ERP Systems: Enhance customer data accuracy by validating and standardizing Japanese addresses within enterprise resource planning or customer relationship management platforms.
• Logistics and Delivery Platforms: Improve route optimization, delivery planning, and last-mile delivery efficiency by ensuring precise address data for Japanese destinations.
• Business Intelligence Tools: Integrate location data for geographical analysis, market segmentation, and data visualization within BI dashboards.
• Data Warehousing: Standardize and enrich address databases in data warehouses for reporting and analytical purposes.

Alternatives

• Mapbox: A global mapping platform offering geocoding, mapping, and navigation APIs, suitable for various regions including Japan, with extensive customization options.
• Google Maps Platform: Provides comprehensive mapping and location services globally, including geocoding and reverse geocoding, with broad coverage and high reliability.
• Esri: A geographic information system (GIS) leader offering robust geocoding capabilities, primarily for enterprise GIS solutions and spatial analysis.
• OpenStreetMap (via third-party APIs): An open-source alternative providing global map data, often accessed through various third-party geocoding APIs built on its dataset.

Getting started

To begin using the SLF Geocoding API, you'll typically need to obtain an API key from SLF after subscribing to a plan. The API is designed around standard HTTP requests, returning data in JSON format. Below is an example of how to make a basic geocoding request using Python, assuming you have an API key and want to convert a Japanese address to coordinates.

This example demonstrates calling the Geocoding API endpoint to process a Japanese address. Replace YOUR_API_KEY with your actual key and YOUR_ADDRESS_ENDPOINT with the specific endpoint provided by SLF for geocoding requests.

import requests
import json

# Replace with your actual API key and endpoint
API_KEY = "YOUR_API_KEY"
GEOCODING_ENDPOINT = "https://api.slf.co.jp/geocoding/v1/address"

# The Japanese address to geocode
address = "東京都千代田区大手町1-5-5"

headers = {
    "Content-Type": "application/json",
    "X-API-KEY": API_KEY # Assuming API key is passed in a header
}

params = {
    "address": address
}

try:
    response = requests.get(GEOCODING_ENDPOINT, headers=headers, params=params)
    response.raise_for_status() # Raise an exception for HTTP errors

    data = response.json()

    if data and data.get("status") == "OK":
        # Assuming the response structure includes 'results' with lat/lng
        results = data.get("results", [])
        if results:
            first_result = results[0]
            latitude = first_result.get("latitude")
            longitude = first_result.get("longitude")
            print(f"Address: {address}")
            print(f"Latitude: {latitude}, Longitude: {longitude}")
        else:
            print("No geocoding results found for the address.")
    else:
        print(f"Error geocoding address: {data.get('message', 'Unknown error')}")

except requests.exceptions.HTTPError as http_err:
    print(f"HTTP error occurred: {http_err}")
    print(f"Response content: {response.text}")
except requests.exceptions.ConnectionError as conn_err:
    print(f"Connection error occurred: {conn_err}")
except requests.exceptions.Timeout as timeout_err:
    print(f"Timeout error occurred: {timeout_err}")
except requests.exceptions.RequestException as req_err:
    print(f"An unexpected error occurred: {req_err}")
except json.JSONDecodeError:
    print(f"Failed to decode JSON response: {response.text}")

This Python script sends a GET request to the SLF Geocoding API with the specified Japanese address. It prints the latitude and longitude if the request is successful. Error handling is included to catch common issues like network problems or API-specific errors. For detailed API specifications, including all available parameters and response formats, refer to the official SLF Geocoding API documentation, which is available in Japanese and provides comprehensive guidance for integration.