AWS Cost Explorer: Visualize and Analyze Cloud Costs with Tags
Learn how to use AWS Cost Explorer to visualize cloud costs and track project-level expenses with cost allocation tags.
Related Exam Domains
- Domain 4: Design Cost-Optimized Architectures
Key Takeaway
AWS Cost Explorer is a free tool that visualizes up to 13 months of cost data, enables detailed analysis with filters/grouping/tags, and forecasts costs up to 18 months ahead. Activate cost allocation tags to track costs by project, team, or environment.
Exam Tip
Exam Essential: "Cost visualization + analysis = Cost Explorer", "Budget setting + alerts = Budgets", "Detailed usage data = Cost and Usage Report"
What is Cost Explorer?
A tool for visually analyzing and forecasting AWS costs and usage.
Core Features
| Feature | Description |
|---|---|
| Cost Visualization | Daily/monthly cost trend charts |
| Filtering | Filter by service, account, region, tags |
| Grouping | Group by service, account, tag |
| Cost Forecasting | AI-based forecast up to 18 months ahead |
| Savings Plans Recommendations | Suggestions based on usage patterns |
| RI Recommendations | Reserved Instance purchase recommendations |
| Cost | Free (API calls are charged per request) |
Cost Analysis Methods
1. Analysis by Service
Cost Explorer → Group by: Service
[Chart Example]
EC2: ████████████████ $500
RDS: ████████████ $350
S3: ████████ $200
Lambda: ████ $100
CloudFront: ███ $80
Other: ██ $50
────────────────────────────────────
Total Cost: $1,280/month
2. Daily Trend Analysis
Cost Explorer → Granularity: Daily
[Chart Example]
$60 │ ╱╲
$50 │ ╱╲ ╱ ╲ ╱╲
$40 │╱╲╱ ╲╱ ╲╱ ╲
$30 │
└──────────────────
1st 7th 14th 21st 28th
→ Identify root cause of cost spikes on specific days
3. Analysis by Account (Multi-Account)
Cost Explorer → Group by: Linked Account
Prod account: ████████████████ $800
Dev account: ████████ $300
Test account: ████ $100
Sandbox: ██ $80
Cost Allocation Tags
What are Tags?
Key-value labels attached to resources for tracking and categorizing costs.
Tag Examples:
EC2 Instance:
- Environment: production
- Project: webapp
- Team: backend
- CostCenter: CC-1234
RDS Instance:
- Environment: production
- Project: webapp
- Team: backend
Tag Types
| Type | Prefix | Description |
|---|---|---|
| User-defined Tags | user: | Tags you create |
| AWS-generated Tags | aws: | Auto-generated by AWS (e.g., aws:createdBy) |
Tag Activation Process
1. Attach tags to resources (EC2, RDS, S3, etc.)
2. Billing Console → Cost Allocation Tags → Activate tags
3. Up to 24 hours for Cost Explorer to reflect
4. Cost Explorer → Filter/Group by tags
Exam Tip
Important: Attaching tags to resources alone isn't enough. You must activate cost allocation tags in Billing Console for them to appear in Cost Explorer.
Tag-based Cost Analysis
Cost Explorer → Group by: Tag (Project)
webapp: ████████████████ $600
api: ████████████ $400
analytics: ████████ $200
internal: ████ $100
────────────────────────────────────
→ Track costs per project
Recommended Tag Strategy
| Tag Key | Purpose | Example Values |
|---|---|---|
Environment | Cost by environment | prod, dev, staging |
Project | Cost by project | webapp, api, ml |
Team | Cost by team | backend, frontend, data |
CostCenter | Cost center | CC-1234 |
Owner | Owner | kim@example.com |
Cost Forecasting
Cost Explorer predicts future costs based on past usage patterns.
Forecast Example:
Current month spending: $1,200 (15 days elapsed)
End of month forecast: $2,400
3-month forecast:
Feb: $2,500
Mar: $2,600
Apr: $2,700
Savings Recommendations
Savings Plans Recommendations
Cost Explorer → Savings Plans Recommendations:
Current On-Demand spending: $1,000/month
Recommended Savings Plans: $700/month commitment
Expected savings: $300/month (30%)
RI Recommendations
Cost Explorer → RI Recommendations:
Current EC2 On-Demand: m5.large × 3 instances (24/7)
Recommendation: Purchase 3 RIs (1-year no upfront)
Expected savings: $2,400/year
Cost Explorer vs Other Cost Tools
| Tool | Purpose | Core Features |
|---|---|---|
| Cost Explorer | Cost visualization/analysis | Charts, filters, forecasting |
| AWS Budgets | Budget setting/alerts | Threshold alerts, auto actions |
| Cost and Usage Report | Detailed usage data | CSV/Parquet detailed data |
| Trusted Advisor | Optimization recommendations | Cost, security, performance checks |
Exam Tip
Tool Selection: "Visualization/Analysis" → Cost Explorer, "Alerts/Budgets" → Budgets, "Detailed CSV" → CUR, "Overall Recommendations" → Trusted Advisor
SAA-C03 Exam Focus Points
- ✅ Cost Visualization: "Service/account cost analysis = Cost Explorer"
- ✅ Tag Activation: "Cost allocation tags must be activated in Billing"
- ✅ Cost Forecasting: "Cost Explorer can forecast future costs"
- ✅ Savings Recommendations: "Built-in Savings Plans/RI recommendations"
- ✅ vs Budgets: "Analysis = Cost Explorer, Alerts = Budgets"
Exam Tip
Sample Exam Question: "How to track and visualize AWS costs by project?" → Answer: Attach project tags to resources → Activate cost allocation tags → Group by tag in Cost Explorer
Frequently Asked Questions (FAQ)
Q: Is Cost Explorer free?
The Cost Explorer UI is free. However, programmatic Cost Explorer API calls are charged $0.01 per request.
Q: Can I see individual resource costs in Cost Explorer?
You can see per-resource-ID costs in hourly granularity, but this is only supported for some services like EC2, RDS. For detailed per-resource costs, use Cost and Usage Report (CUR).
Q: If I add tags later, do they apply to past costs?
No. Tags only apply to costs from the activation point forward. They are not retroactively applied, so it's important to attach tags at resource creation.
Q: How long is Cost Explorer data retained?
Up to 13 months of historical cost data is available. For longer retention, store Cost and Usage Reports in S3.
Q: Can I see all Organization account costs at once?
Yes. Using Cost Explorer from the management account shows consolidated costs for all member accounts. Per-account filtering is also available.