Global Accelerator vs CloudFront: When to Choose What?

Key Takeaway

CloudFront is for HTTP/HTTPS content caching, Global Accelerator is for TCP/UDP traffic acceleration and when static IPs are needed. Choose CloudFront for cacheable web content, Global Accelerator for non-HTTP workloads like gaming/IoT/VoIP.

Exam Tip

Exam Essential: "Caching needed = CloudFront", "Static IP or non-HTTP = Global Accelerator"

What Both Services Have in Common

Both services leverage the AWS global network and edge locations.

[User] ──── Public Internet ──── [Origin] (slow and unstable)

        vs

[User] ── Edge Location ── AWS Backbone ── [Origin] (fast and stable)

Common Benefits

450+ edge locations worldwide
AWS Shield basic DDoS protection
Uses AWS private backbone instead of public internet
Reduced latency for global users

Key Differences Comparison

Comparison	CloudFront	Global Accelerator
Layer	Layer 7 (Application)	Layer 4 (Network)
Protocols	HTTP/HTTPS	TCP, UDP (including HTTP)
Caching	✅ Supported	❌ Not supported
IP Address	Dynamic (can change)	2 static Anycast IPs
WAF Integration	✅ Direct integration	Indirect via ALB
Lambda@Edge	✅ Supported	❌ Not supported
Failover	Origin failover	Automatic cross-region failover
Health Checks	Origin groups	Endpoint health checks

When to Use CloudFront?

Suitable Use Cases

Static Content Delivery
- Images, CSS, JavaScript, videos
- Used with S3 origin
Dynamic Web Applications
- API acceleration (even without caching)
- Dynamic HTML pages
Media Streaming
- HLS, DASH streaming
- Live and on-demand video
Security Requirements
- Need AWS WAF integration
- Request/response transformation with Lambda@Edge

CloudFront Architecture:

[User] → [Edge Location] → [Cache HIT] → Immediate response
                │
                └── [Cache MISS] → [Origin (S3/ALB/EC2)]

Exam Tip

CloudFront + S3: Standard pattern for static website hosting

When to Use Global Accelerator?

Suitable Use Cases

Non-HTTP Workloads
- Online gaming (UDP)
- IoT applications (MQTT)
- VoIP (SIP/RTP)
Static IP Needed
- Firewall whitelist configuration
- DNS caching issue avoidance
- Hardcoded IP in client applications
Fast Cross-Region Failover
- Active-Active multi-region deployment
- Automatic failover within 30 seconds
Financial Trading Platforms
- Millisecond latency critical
- Stable network path needed

Global Accelerator Architecture:

[User] → [Static Anycast IP]
                │
                ▼
        [Edge Location]
                │
                ▼ (AWS Backbone Network)
        ┌───────┴───────┐
        ▼               ▼
   [Region A]       [Region B]
   ALB/NLB/EC2     ALB/NLB/EC2
   (Active)        (Standby)

Exam Tip

Static IP: Global Accelerator provides 2 unchanging Anycast IPs.

Detailed Comparison: What for Which Situation?

Scenario 1: Global Website

Requirement	Recommended Service
Static assets (images, CSS, JS)	CloudFront (caching)
API responses	CloudFront (cacheable)
WAF protection needed	CloudFront (direct integration)

Scenario 2: Real-time Game Server

Requirement	Recommended Service
UDP protocol	Global Accelerator
Low latency	Global Accelerator
Cross-region failover	Global Accelerator

Scenario 3: Financial Trading Platform

Requirement	Recommended Service
Millisecond latency	Global Accelerator
Static IP (firewall)	Global Accelerator
HTTPS API	Both possible (GA recommended)

Scenario 4: Hybrid Usage

In many cases, you can use both services together:

[Static Content] → CloudFront → S3

[Dynamic API] → Global Accelerator → ALB → EC2

Cost Comparison

CloudFront Costs

Item	Cost
Data Transfer	$0.085-$0.250/GB (by region)
HTTP Requests	$0.0075-$0.016/10K
HTTPS Requests	$0.01-$0.022/10K
Invalidation	1,000/month free, then $0.005/path

Global Accelerator Costs

Item	Cost
Fixed Fee	$0.025/hour (~$18/month)
Data Transfer (DT-Premium)	$0.015-$0.105/GB (by region)

Exam Tip

Cost Difference: CloudFront is usage-based, Global Accelerator is fixed fee + usage

Performance Comparison

Latency Improvement Effect

Route	CloudFront	Global Accelerator
Same region	10-30% improvement	10-20% improvement
Cross-continent	40-60% improvement (with caching)	20-40% improvement
Opposite side of globe	50-80% improvement (with caching)	30-50% improvement

Failover Time

Service	Failover Time
CloudFront	Depends on origin group settings
Global Accelerator	Under 30 seconds (health check based)

SAA-C03 Exam Focus Points

✅ Protocol Distinction: "HTTP/HTTPS → CloudFront", "TCP/UDP → Global Accelerator"
✅ Caching Requirement: "Caching needed → CloudFront", "No caching needed → Both possible"
✅ Static IP: "Static IP needed → Global Accelerator"
✅ WAF Integration: "Direct WAF integration → CloudFront"
✅ Failover: "Fast cross-region failover → Global Accelerator"

Exam Tip

Sample Exam Question: "You need to reduce latency for a global online game (UDP) and require automatic failover within 30 seconds on region failure. What is the appropriate service?" → Answer: Global Accelerator (UDP support + fast failover)

Frequently Asked Questions

Q: Can I use both services simultaneously?

Yes. It's common to separate static content to CloudFront and dynamic application traffic to Global Accelerator.

Q: Do Global Accelerator's static IPs ever change?

No. IP addresses don't change unless you delete the Accelerator. You can also use BYOIP (Bring Your Own IP) for your own IPs.

Q: Doesn't CloudFront also support TCP acceleration?

CloudFront supports HTTP/HTTPS (TCP-based), but not pure TCP/UDP protocols (gaming, IoT).

Q: Which service is faster?

For cacheable content, CloudFront is much faster (no origin access on cache HIT). For non-cacheable dynamic content, they're similar or Global Accelerator has a slight edge.

Q: Should I use with Route 53?

CloudFront provides its own domain, so connect with Route 53 Alias record. Global Accelerator provides static IPs, so connect directly with A record or use the IPs without DNS.