A Guide for Creating a Custom Domain for Amazon API Gateway

Overview

A custom domain name plays a crucial role in presenting a polished and consistent identity for your applications. When working with Amazon API Gateway, the service automatically generates long and complex default URLs that are not ideal for production use. By configuring a custom domain, such as api.example.com, you can provide users and clients with a clean, branded, and secure endpoint for accessing your APIs.

This setup not only elevates the user experience but also enhances security and API lifecycle management. AWS offers a seamless way to integrate custom domains using AWS Certificate Manager (ACM) for SSL/TLS certificates, Amazon API Gateway for routing, and Amazon Route 53 (or any external DNS provider) for domain resolution. Whether you’re hosting a single microservice or multiple API versions, a custom domain simplifies URL management and strengthens your architecture’s reliability.

This guide walks you through the complete process, requesting certificates, setting up the domain in Amazon API Gateway, creating base path mappings, and configuring DNS, ensuring you can implement a production-ready custom domain with confidence and ease.

Introduction

In today’s cloud-driven world, APIs are at the core of almost every modern application, enabling seamless communication between services, systems, and users. Amazon API Gateway is one of the most widely used fully managed services for creating, deploying, and managing APIs at scale. However, the default URLs generated by Amazon API Gateway are long, difficult to remember, and not ideal for production environments.

Step-by-Step Guide: How to Create a Custom Domain for Amazon API Gateway

Step 1: Request an SSL/TLS Certificate in AWS ACM

Open AWS Certificate Manager (ACM) → choose Request a Public Certificate.

Enter your domain

Select DNS validation.

Add the provided CNAME record to Amazon Route 53 or an external DNS server.

Wait until the certificate shows Issued.

Step 2: Create a Custom Domain Name in Amazon API Gateway

Open Amazon API Gateway → Custom Domain Names

Click Create Custom Domain

Enter: api.example.com

Select endpoint type: Regional (recommended) or Edge-Optimized

Choose the ACM certificate you created

Save to generate the API Gateway target domain name, e.g.:

d-xyz123.cloudfront.net

Step 3: Add Base Path Mapping

Open your custom domain

Select Configure Base Path Mapping

Choose your API and stage (dev/test/prod)

Provide a base path or leave blank for root mapping

Save your configuration

Example:

api.example.com/v1/orders

Step 4: Update DNS Records

Using Amazon Route 53

Go to your Hosted Zone

Create A Record → Alias → API Gateway Domain Name

Save

Using External DNS

Create a CNAME:

Name: api.example.com

Type: CNAME

Value: d-xyz123.cloudfront.net

TTL: 300

Step 5: Test the Custom Domain

Open:

https://api.example.com

Or (if mapped):

https://api.example.com/v1/resource

Your API should now be accessible via the custom domain.

Conclusion

Configuring a custom domain for Amazon API Gateway is one of the most effective ways to elevate the professionalism, security, and usability of your API endpoints. By integrating AWS Certificate Manager for SSL/TLS, leveraging Amazon API Gateway’s domain features, and mapping your DNS records using Amazon Route 53 or any external DNS provider, you gain full control over how users access your APIs.

A well-configured custom domain not only improves user confidence but also supports better versioning, cleaner routing, and long-term scalability for your backend services. Whether you’re developing a small application or managing multiple microservices, using a custom domain ensures your API architecture is production-ready and aligned with industry best practices.

With this setup in place, you can now build reliable, secure, and beautifully structured APIs that strengthen your brand identity and enhance the overall developer experience.

Drop a query if you have any questions regarding Amazon API Gateway and we will get back to you quickly.

About CloudThat