How to improve performance of a static website hosted on AWS S3?

While the previous answer correctly highlights the benefits of CloudFront's global reach, there are three specific configurations you should implement to get the most out of your puzzle site:

• Enable Brotli/Gzip Compression: In your CloudFront Cache Behavior settings, make sure "Compress Objects Automatically" is set to Yes. For a text-heavy site (HTML, JS, CSS), this can reduce file sizes by up to 70%, which is a huge win for mobile users on slower networks.
• Leverage HTTP/2 or HTTP/3: CloudFront supports these protocols by default. They allow for "multiplexing" (loading multiple assets over a single connection), which will make your puzzle’s assets load much faster than a standard S3 connection.
• Use AWS Certificate Manager (ACM): Since you are using CloudFront, you can get a free SSL certificate through ACM. This allows you to serve your site over HTTPS (essential for modern SEO and user trust) and is required to take advantage of the performance benefits of HTTP/2.
• Cache Invalidation Strategy: Keep in mind that CloudFront "remembers" your files. If you update your puzzle logic and upload it to S3, users might still see the old version. You can either manually create an Invalidation in the CloudFront console or, better yet, use "cache busting" (e.g., naming your file script.v1.js) for instant updates.

One final tip: Look into Origin Access Control (OAC). This allows you to make your S3 bucket private so that users must go through CloudFront to see your site. This prevents people from bypassing your cache and helps keep your S3 request costs low.

Yes, Amazon CloudFront will significantly improve global performance for your S3-hosted static site.

S3 serves content from a single region. CloudFront caches it at 450+ edge locations worldwide, so users get served from the nearest point of presence — typically reducing TTFB from 100-400ms to under 20ms for cached content.

Key Configuration Steps

1. Set Up CloudFront with Origin Access Control (OAC)

Rather than exposing your S3 bucket publicly via static website hosting, use OAC to keep the bucket private and serve all traffic through CloudFront. This:

• Forces users through the CDN (no cache bypass)
• Reduces S3 request costs
• Improves security posture

2. Enable Compression

Set "Compress Objects Automatically" to Yes in your Cache Behavior settings. CloudFront will serve Brotli or Gzip depending on the client's Accept-Encoding header. For text-heavy assets (HTML, JS, CSS), this reduces transfer size by up to 70%.

3. Set Proper Cache Headers on S3 Objects

Static assets (JS, CSS, images, fonts) Cache-Control: max-age=31536000, immutable Use versioned filenames (e.g., app.a3f2b1.js) so you can cache indefinitely.

HTML files Cache-Control: max-age=300 or no-cache Short TTL ensures users always get the latest page structure.

Use the CachingOptimized managed cache policy in CloudFront for a sensible default.

4. Use Cache Busting for Updates

CloudFront caches files based on URL. If you update your puzzle logic, users may still see the old version until the TTL expires. Two options:

• Recommended: Version your filenames (script.a3f2b1.js) — instant updates, no invalidation needed
• Fallback: Create a CloudFront invalidation (/*) — takes a few minutes to propagate, first 1,000/month are free

5. Enable HTTP/2 and HTTP/3

• HTTP/2 is on by default — enables multiplexing (multiple assets over one connection)
• HTTP/3 (QUIC) is opt-in — further reduces connection setup latency, especially on mobile networks

6. HTTPS via ACM

Request a free certificate in AWS Certificate Manager (must be in us-east-1 for CloudFront). This gives you HTTPS, which is required for HTTP/2, improves SEO, and builds user trust.

7. DNS with Route 53

Point your domain to CloudFront using a Route 53 Alias record — this eliminates an extra DNS hop and has zero query cost.

Architecture Summary

User → CloudFront Edge (cached, compressed, HTTP/2-3) ↑ Alias record (Route 53) ↑ ACM certificate (HTTPS) ↓ OAC S3 Bucket (private, origin)

Expected Results

For a static puzzle site like yours:

• TTFB: 100-400ms → 5-20ms (edge cache hit)
• Transfer size: 50-70% smaller with compression
• Global consistency: Similar performance regardless of user location

CloudFront's free tier (1 TB transfer + 10M requests/month) will comfortably cover a small project.

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Sources:

• Speeding up your website with Amazon CloudFront (https://docs.aws.amazon.com/AmazonS3/latest/userguide/website-hosting-cloudfront-walkthrough.html)
• Best Practices: Optimizing Amazon S3 Performance (https://docs.aws.amazon.com/AmazonS3/latest/userguide/optimizing-performance.html)
• Using Alternate Domain Names with CloudFront (https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/CNAMEs.html)