How to Configure CloudFront

Amazon CloudFront is a global content delivery network (CDN) service that securely delivers data, videos, applications, and APIs to customers worldwide with low latency and high transfer speeds. By caching content at edge locations closer to end users, CloudFront reduces the load on origin servers, improves website performance, and enhances user experience. Configuring CloudFront correctly is essential for optimizing speed, security, and scalability—especially for high-traffic websites, e-commerce platforms, streaming services, and SaaS applications.

Many organizations underestimate the complexity of CloudFront configuration, assuming it’s a simple “set and forget” service. In reality, improper setup can lead to security vulnerabilities, caching issues, broken assets, or increased costs. This guide provides a comprehensive, step-by-step walkthrough of how to configure CloudFront effectively—from initial setup to advanced optimizations—ensuring you maximize performance while minimizing risks.

Step-by-Step Guide

Prerequisites

Before configuring CloudFront, ensure you have the following:

• An active AWS account with appropriate permissions (preferably an IAM user with CloudFront and S3 access)
• A registered domain name (optional but recommended for custom origins)
• A content origin: an S3 bucket, an HTTP server (EC2, ELB, or on-premises), or an API Gateway endpoint
• SSL/TLS certificate from AWS Certificate Manager (ACM) if using HTTPS

CloudFront supports multiple origin types, but for most use cases, an S3 bucket is the most common and cost-effective choice. If you’re serving dynamic content, you may use an Application Load Balancer, EC2 instance, or custom origin server.

Step 1: Create or Identify Your Origin

Your origin is the source of the content that CloudFront will cache and deliver. The most common origin is an Amazon S3 bucket.

To create an S3 bucket:

1. Log in to the Amazon S3 Console.
2. Click Create bucket.
3. Enter a globally unique bucket name (e.g., mywebsite-assets-2024).
4. Select a region close to your primary audience (e.g., us-east-1 or eu-west-1).
5. Uncheck Block all public access if you intend to serve static content publicly. If you plan to use signed URLs or signed cookies for restricted access, leave this enabled and configure access policies later.
6. Click Create bucket.

Upload your static assets (HTML, CSS, JS, images, videos) into the bucket. Organize them in folders for easier management (e.g., /images/, /css/, /js/).

If you’re using a custom origin (e.g., an EC2 instance or load balancer), ensure:

• The origin server is publicly accessible (or configured with a VPC endpoint if private)
• HTTP/HTTPS ports (80/443) are open in the security group
• The server responds correctly to requests with proper headers (e.g., Cache-Control, ETag)

Step 2: Create a CloudFront Distribution

Now, navigate to the CloudFront Console and click Create Distribution.

You’ll see two types of distributions: Web and RTMP. Select Web for standard website and API delivery.

Origin Settings

In the Origin Settings section:

• For an S3 origin: Select your bucket from the dropdown. CloudFront will auto-fill the origin domain name.
• For a custom origin: Enter the domain name of your server (e.g., api.example.com or the public DNS of your load balancer).
• Set Origin ID to a descriptive name (e.g., MyS3BucketOrigin).
• Set Origin Protocol Policy to HTTPS Only if your origin supports HTTPS. This ensures secure communication between CloudFront and your origin.
• Set Origin Shield to Enabled if you have high traffic. Origin Shield reduces load on your origin by acting as an intermediate cache layer in a single AWS region.

Default Cache Behavior Settings

This is one of the most critical sections. The default cache behavior determines how CloudFront handles requests that don’t match any other cache behaviors you’ll define later.

• Viewer Protocol Policy: Set to Redirect HTTP to HTTPS to enforce secure connections.
• Allowed HTTP Methods: Select GET, HEAD, OPTIONS for static content. If you’re serving APIs, add PUT, POST, PATCH, DELETE.
• Cache Based on Selected Request Headers: Choose None for static assets. If your application relies on query strings or cookies, select Whitelist and specify headers (e.g., Authorization, Cookie).
• Object Caching: Set to Use Origin Cache Headers if your origin sends proper Cache-Control headers. Alternatively, use Customize and set a default TTL (e.g., 86400 seconds = 24 hours).
• Origin Request Policy: Select AllViewer if you need to pass headers, cookies, or query strings to the origin. For static content, use None.
• Response Headers Policy: Consider applying a pre-defined policy like SecurityHeaders to add security headers (e.g., Strict-Transport-Security, X-Content-Type-Options).
• Compress Objects Automatically: Enable this to automatically compress files (e.g., HTML, CSS, JS) using GZIP or Brotli when requested by the viewer.

General Settings

• Domain Name: Leave as default (CloudFront will assign a domain like xxxx.cloudfront.net).
• SSL Certificate: Select ACM Certificate and choose a certificate issued in the US East (N. Virginia) region. You must request or import a certificate in ACM before this step.
• Alternate Domain Names (CNAMEs): Enter your custom domain (e.g., cdn.example.com) if you plan to use one.
• Default Root Object: Enter index.html if serving a single-page application or static site.
• Logging: Enable if you need detailed access logs. Specify an S3 bucket to store logs. Logs help with debugging, analytics, and security audits.
• Price Class: Choose based on your audience. Use All Edge Locations for global coverage. Use Only North America and Europe reduces cost if your users are concentrated there.

Advanced Settings

For most users, the defaults are sufficient. However, consider:

• Origin Failover: Configure a secondary origin if high availability is critical (e.g., S3 bucket in another region).
• Origin Groups: Useful for failover scenarios where you have multiple origins (e.g., primary S3, secondary EC2).

Click Create Distribution. CloudFront will begin provisioning your distribution. This process typically takes 10–15 minutes but may take up to 30 minutes in rare cases. You’ll see a status of In Progress. Once it changes to Deployed, your distribution is live.

Step 3: Configure DNS (Optional but Recommended)

If you’re using a custom domain (e.g., cdn.example.com), update your DNS records to point to your CloudFront distribution.

In your domain registrar or DNS provider (e.g., Route 53, Cloudflare, GoDaddy):

1. Create a CNAME record:
2. Name: cdn (or your subdomain)
3. Type: CNAME
4. Value: Your CloudFront domain (e.g., d111111abcdef8.cloudfront.net)
5. TTL: 3600 seconds (1 hour)

Wait for DNS propagation (typically under 5 minutes, but up to 48 hours globally).

Step 4: Test Your Configuration

Once deployed, test your CloudFront distribution:

• Visit your CloudFront URL (e.g., https://d111111abcdef8.cloudfront.net/image.jpg) and verify the asset loads.
• Use browser developer tools to inspect the response headers. Look for X-Cache: Hit from cloudfront to confirm caching is working.
• Check the Age header—this indicates how long the object has been cached in CloudFront.
• Use tools like KeyCDN’s CDN Test Tool or WebPageTest to validate performance improvements.
• Verify HTTPS is enforced by accessing your site via HTTP—it should redirect to HTTPS.

Step 5: Configure Cache Invalidation (When Needed)

CloudFront caches content based on TTL. If you update a file (e.g., main.js), users may still receive the old version until the TTL expires.

To force an update:

1. In the CloudFront console, select your distribution.
2. Go to the Invalidations tab.
3. Click Create Invalidation.
4. Enter the path of the file(s) to invalidate:
• /images/logo.png — invalidates one file
• /css/* — invalidates all CSS files
• /* — invalidates everything (use sparingly; costs apply)

5. Click Invalidate.

Invalidations are processed within a few minutes. Note: AWS provides 1,000 free invalidations per month. Additional invalidations incur charges.

Step 6: Secure Your Distribution

Security is non-negotiable. Here’s how to harden your CloudFront setup:

• Restrict S3 Access: If using S3 as origin, remove public access and use an Origin Access Identity (OAI). In CloudFront, under Origin Settings, select Create a new OAI and apply it. Then, update your S3 bucket policy to allow access only from the OAI.
• Use Signed URLs or Signed Cookies: For private content (e.g., paid videos, documents), generate signed URLs using AWS SDKs or CLI. This ensures only authorized users can access content.
• Enable WAF Integration: Attach an AWS Web Application Firewall (WAF) to your distribution to block common attacks (SQL injection, XSS, bots).
• Restrict Viewer Access: Use Origin Request Policy and Response Headers Policy to enforce security headers like CSP, X-Frame-Options, and Referrer-Policy.
• Disable Insecure Protocols: In the Viewer Protocol Policy, disable HTTP entirely if possible.

Best Practices

1. Optimize Cache Headers at the Origin

CloudFront respects the Cache-Control and Expires headers sent by your origin. Always configure these properly:

• Cache-Control: public, max-age=31536000 — for static assets with versioned filenames (e.g., app.a1b2c3.js)
• Cache-Control: public, max-age=3600 — for frequently updated assets
• Cache-Control: no-cache — for HTML files that change often
• Cache-Control: no-store — for sensitive data (e.g., user dashboards)

Use versioned filenames (e.g., style.1.2.3.css) to enable long-term caching without invalidation.

2. Use Origin Shield for High-Traffic Sites

Origin Shield reduces the number of requests reaching your origin by caching at a regional edge. This is especially useful if your origin is slow, expensive, or has limited throughput. Enable it in your origin settings—it’s free and requires no additional configuration.

3. Leverage Compression

Enable Compress Objects Automatically in your cache behavior. CloudFront compresses files like HTML, CSS, JS, JSON, and XML using GZIP or Brotli. This reduces bandwidth usage and speeds up delivery. Brotli typically offers 15–20% better compression than GZIP.

4. Use Multiple Cache Behaviors for Different Content Types

Instead of relying on a single default behavior, create specific cache behaviors for different paths:

• /images/* → TTL: 1 year, compress enabled
• /api/* → TTL: 0 seconds, forward all headers
• /admin/* → TTL: 0 seconds, require authentication

This allows fine-grained control over caching and security policies.

5. Monitor Performance and Costs

Use AWS CloudWatch to monitor key metrics:

• Requests — total number of viewer requests
• Bytes Downloaded — bandwidth usage
• Cache Hit Rate — percentage of requests served from edge cache
• 4xx and 5xx Errors — identify broken links or origin issues

Set up CloudWatch alarms for unusual spikes in traffic or errors.

6. Avoid Over-Caching Dynamic Content

Never cache personalized content (e.g., user dashboards, shopping carts) unless you’re using signed cookies or token-based authentication. Use cache behaviors with TTL=0 for dynamic endpoints.

7. Regularly Audit Your Distribution

Quarterly, review:

• Unused CNAMEs
• Expired SSL certificates
• Unused invalidations
• Overly permissive S3 bucket policies
• WAF rules and rate limiting

Tools and Resources

AWS Console

The primary interface for configuring CloudFront. Always use the latest version for access to new features like Origin Shield and Response Headers Policies.

AWS CLI

Automate CloudFront configuration using the AWS Command Line Interface. Useful for CI/CD pipelines.

Example: Create a distribution via CLI

aws cloudfront create-distribution --distribution-config file://dist-config.json

Where dist-config.json contains your full configuration in JSON format.

AWS SDKs

Use AWS SDKs (Python, Node.js, Java, etc.) to programmatically manage distributions, invalidate caches, or generate signed URLs.

CloudFront Access Logs

Enable access logging to an S3 bucket. Logs include detailed information about every request: IP address, timestamp, status code, user agent, and more. Use tools like Amazon Athena or Splunk to analyze logs for security or performance insights.

Third-Party Tools

• KeyCDN CDN Test — checks if your content is being served via CDN and from the correct location
• WebPageTest — measures load times across global locations
• GTmetrix — analyzes performance and provides optimization suggestions
• SSL Labs — tests SSL/TLS configuration of your CloudFront endpoint
• Cloudflare Spectrum — if you use Cloudflare as a proxy, ensure proper integration with CloudFront

Documentation and References

• AWS CloudFront Developer Guide
• CloudFront Pricing
• S3 Bucket Policies for CloudFront
• WAF with CloudFront

Real Examples

Example 1: Static Website Hosting with S3 and CloudFront

A company hosts a marketing website with HTML, CSS, JS, and images on an S3 bucket. They want global delivery with HTTPS and fast load times.

Configuration:

• Origin: S3 bucket named marketing-site-2024
• Origin Access Identity (OAI) enabled
• S3 bucket policy grants access only to the OAI
• CloudFront distribution with custom domain www.marketingcompany.com
• SSL certificate from ACM
• Default cache behavior: TTL = 24 hours, compress enabled, redirect HTTP to HTTPS
• Cache behavior for /assets/*: TTL = 1 year, compress enabled
• Logging enabled to S3 bucket cf-logs-marketing
• WAF attached to block common web exploits

Result: Page load time reduced from 3.2s to 0.8s globally. Bandwidth costs reduced by 40% due to caching and compression.

Example 2: API Gateway + CloudFront for Mobile App Backend

A mobile app uses an API Gateway endpoint to serve user data. The app needs low-latency access and rate limiting.

Configuration:

• Origin: API Gateway endpoint https://abc123.execute-api.us-east-1.amazonaws.com/prod
• Viewer Protocol Policy: HTTPS Only
• Allowed Methods: GET, POST, PUT, DELETE
• Cache Based on Request Headers: Whitelist Authorization and Accept
• Origin Request Policy: Forward all headers
• Cache Behavior: TTL = 0 seconds (no caching)
• WAF attached to limit requests to 1000 per minute per IP
• Origin Shield enabled

Result: API response time improved from 220ms to 95ms for users in Asia. Bot traffic reduced by 70% due to WAF rate limiting.

Example 3: Video Streaming with Signed URLs

A media company delivers premium video content exclusively to paying subscribers.

Configuration:

• Origin: S3 bucket with private videos
• OAI enabled, S3 bucket policy restricted to OAI
• CloudFront distribution with custom domain videos.example.com
• SSL certificate from ACM
• Cache behavior: TTL = 3600 seconds (1 hour)
• Use signed URLs generated via Node.js backend using AWS SDK
• URLs expire after 1 hour
• WAF blocks known bad user agents and IPs

Result: Unauthorized access attempts reduced to zero. No content leaks. Subscribers experience seamless playback with low buffering.

FAQs

How long does it take for CloudFront to deploy?

Typically 10–15 minutes, but it can take up to 30 minutes. Changes to cache behaviors or origin settings may require additional time to propagate globally.

Can I use CloudFront with a non-AWS origin?

Yes. CloudFront supports any HTTP/HTTPS server as an origin, including on-premises servers, Google Cloud Storage, or Azure Blob Storage. Ensure the origin is publicly reachable or configured with a VPC endpoint.

Does CloudFront support HTTP/2 and HTTP/3?

Yes. CloudFront supports HTTP/2 and HTTP/3 (QUIC) automatically for all distributions. No configuration is required.

How do I know if CloudFront is caching my content?

Check the response headers in your browser’s developer tools. Look for X-Cache: Hit from cloudfront. If you see Miss from cloudfront, the object was not cached.

Is CloudFront cheaper than serving directly from S3?

For global audiences, yes. CloudFront reduces bandwidth costs by caching content at edge locations and reduces origin load. For small, localized audiences, direct S3 delivery may be cheaper. Use the AWS Pricing Calculator to compare.

Can I use CloudFront with WordPress?

Yes. Use plugins like W3 Total Cache or WP Super Cache to integrate with CloudFront. Configure the plugin to serve static assets (CSS, JS, images) via CloudFront and set proper cache headers.

What’s the difference between Origin Shield and CloudFront?

CloudFront is the global CDN with 450+ edge locations. Origin Shield is an optional intermediate cache layer in a single AWS region that sits between CloudFront and your origin. It reduces origin load by serving repeated requests from a regional cache instead of hitting your origin directly.

Do I need to invalidate the cache every time I update a file?

No—if you use versioned filenames (e.g., app.v2.js), you can set long TTLs and avoid invalidations entirely. Invalidations are only needed if you cannot change filenames (e.g., app.js).

Can CloudFront serve dynamic content?

Yes. While CloudFront is optimized for static content, it can proxy dynamic requests to origin servers (e.g., Lambda@Edge, API Gateway, EC2). Use cache behaviors with TTL=0 for dynamic paths.

What happens if my origin goes down?

CloudFront will continue serving cached content until the TTL expires. If no content is cached, users will receive a 502 or 504 error. To improve availability, enable Origin Shield and configure a secondary origin.

Conclusion

Configuring Amazon CloudFront is not just about enabling a CDN—it’s about architecting a secure, scalable, and high-performance delivery system for your digital assets. From choosing the right origin and optimizing cache headers to enforcing security policies and monitoring performance, every decision impacts user experience and operational cost.

This guide has walked you through the complete process—from initial setup to advanced optimizations—equipping you with the knowledge to deploy CloudFront confidently. Whether you’re serving static websites, APIs, or premium video content, the principles remain the same: cache intelligently, secure rigorously, and monitor continuously.

Remember: The best CloudFront configurations are those that align with your content type, audience geography, and security requirements. Avoid one-size-fits-all setups. Test thoroughly. Iterate based on data. And always prioritize the end user’s experience.

With proper configuration, CloudFront transforms your website from a slow, unreliable service into a fast, resilient global platform—ready to scale with your business.