AWS Cost Explorer

What it is

AWS Cost Explorer is a tool in the Billing and Cost Management console for viewing and analyzing your costs and usage. It draws charts and tables of what you have spent, lets you slice the data by service, account, RegionAWS RegionA separate geographic area where AWS runs its services, such as us-east-1 in Northern Virginia, made up of several Availability Zones. Most resources live in one Region; you choose Regions for latency, data residency, and the services you need.Glossary entryClose, tag, and many other dimensions, and forecasts what you are likely to spend. It also shows how well your Savings Plans and Reserved InstancesRI (Reserved Instance)A billing discount for committing to an instance type in a Region or Availability Zone for one or three years. It is not an instance: running instances that match are billed at the lower rate. AWS now recommends Savings Plans instead.Glossary entryClose are used, and recommends new ones to buy.

Use it to answer questions such as "Which service grew the most last month?", "Which member account spends the most on EC2?", or "What will our bill be next quarter?"

Concepts and features

Time range and granularity

• By default, Cost Explorer shows the current month and up to the previous 13 months, at daily or monthly granularity.
• You can turn on multi-year data, up to 38 months at monthly granularity, and granular data: hourly and resource-level data for the previous 14 days. Granular data is charged.
• Data is refreshed at least once every 24 hours.

Filtering and grouping

Cost Explorer filters and groups costs by dimensions such as Service, Linked account, Region, Availability ZoneAZ (Availability Zone)An isolated location within an AWS Region, made up of one or more data centers with their own power, cooling, and networking. The AZs in a Region are linked by fast, low-latency connections, so spreading resources across them protects against the failure of one site.Glossary entryClose, Instance type, Usage type, Purchase option (On-Demand, Reserved, Spot), Charge type, Tag, and Cost category. Filters can be combined, for example Linked account and Service to find which account spends most on Amazon EC2. Usage type groups such as EC2: Data Transfer - Inter AZ or EC2: NAT GatewayNAT gatewayA managed VPC component that lets instances in private subnets start connections to the internet or other networks, while blocking connections started from outside. It is billed per hour and per gigabyte processed.Glossary entryClose - Data Processed help find hidden data transfer costs.

To group by your own labels, activate cost allocation tags first; Cost Explorer shows only tags that are active. In an organization, only the management account can activate them. A new tag key can take up to 24 hours to appear for activation and up to 24 hours more to activate, and costs carry the tag only from activation on, unless the management account requests a backfill of up to 12 months. Cost categories group accounts, tags, and services into business units or teams.

Cost views

You can show costs in different ways. Unblended costs show charges as they were billed, for example a Savings Plan's upfront fee on the day you bought it. Amortized costs spread upfront fees across the term, which shows the effective daily cost of usage covered by Savings Plans and Reserved Instances. Net costs include discounts.

Forecasts

Cost Explorer forecasts your spend for up to 18 months, based on your past usage, with an 80% prediction interval. Accounts with less than one full billing cycle of data may not get a forecast. The more steady your past spend, the narrower the forecast range.

Reports and recommendations

• Savings Plans and Reserved Instance reports show utilization (how much of what you bought you are using) and coverage (how much of your eligible usage they cover).
• Savings Plans and Reserved Instance recommendations suggest what to buy, based on your past usage.
• Rightsizing recommendations find idle and underutilized EC2 instances to stop or downsize. They cover only EC2 instances; for EBS volumes, Lambda functions, Auto Scaling groups, ECS services on Fargate, and other resources, use AWS Compute Optimizer, which sizes them from CloudWatch utilization metrics. AWS now recommends Cost Optimization Hub for cost optimization recommendations across services.

Security, resilience, performance, and cost

Security

• In AWS Organizations, Cost Explorer is enabled from the management account, which turns it on for all member accounts.
• The management account sees costs for every account; each member account sees only its own costs. The management account can turn off member accounts' access (all or none) in Cost Management preferences.
• IAM policies grant or deny individual users access to Cost Explorer and to billing data.

Resilience and performance

• Cost data can lag behind usage, because services report billing data at different times. For near-real-time alerts, use AWS Budgets or Cost Anomaly Detection rather than checking Cost Explorer.
• Forecasts for new organization accounts improve once their spending patterns are known.

Cost

• The Cost Explorer console is free.
• The Cost Explorer APIAPI (Application programming interface)A defined way for one program to ask another for data or actions, such as a set of HTTPS requests and responses. Every AWS service is controlled through its API, which the console, the CLI, and the SDKs call for you.Glossary entryClose costs $0.01 per paginated request.
• Hourly and resource-level granular data is charged per usage record.

Monitoring

• Cost Explorer is itself a monitoring tool for spend. Pair it with AWS Budgets for alerts, Cost Anomaly Detection for unexpected spikes, and the Cost and Usage Report for detailed analysis.

Cost Explorer or another tool?

If the requirement is	Choose
Visualize and analyze costs, and forecast spend, in the console	AWS Cost Explorer
Get an alert or take action when spend crosses a limit	AWS Budgets
Get every line item, with resource IDs, for SQLSQL (Structured Query Language)The standard language for querying and changing data in relational databases. Analytics services such as Amazon Athena and Amazon Redshift also use SQL.Glossary entryClose analysis	Cost and Usage Report
Be told about an unexpected spike in spend	Cost Anomaly Detection
See which Savings Plan to buy	Savings Plans recommendations, in Cost Explorer or the Billing console
Find over-provisioned EC2 instances, EBS volumes, or Lambda functions	AWS Compute Optimizer or Cost Optimization Hub

Reverse mindmap: when the question points here

• Yes, when the question says
  • Visualize monthly costs by service→ leads to Cost Explorer
  • Which member account spends most on EC2→ leads to Filter by linked account and service
  • Forecast spend for the next quarter→ leads to Cost Explorer forecast
  • Costs per project or cost center→ leads to Group by an activated cost allocation tag
  • Tag costs for months before activation→ leads to Cost allocation tag backfill, up to 12 months
• Use its reports
  • Are our Savings Plans being used→ leads to Savings Plans utilization report
  • How much usage is covered by commitments→ leads to Coverage report
  • Which Savings Plan should we buy→ leads to Savings Plans recommendations
• Get more detail
  • Hourly costs for the last two weeks→ leads to Granular data, charged
  • More than 13 months of history→ leads to Multi-year data
  • Query costs programmatically→ leads to Cost Explorer API, $0.01 per request
• No, when the question says
  • Alert before spend exceeds a limit→ leads to AWS Budgets
  • Every line item delivered to S3→ leads to Cost and Usage Report
  • Unexpected spike detected by machine learning→ leads to Cost Anomaly Detection
  • Rightsize EBS volumes or Lambda functions→ leads to AWS Compute Optimizer

Key takeaways

• Cost Explorer charts and filters your costs for the past 13 months by default, and forecasts up to 18 months ahead.
• Group by service, account, Region, usage type, tag, or cost category; tags must be activated as cost allocation tags first.
• It shows Savings Plans and Reserved Instance utilization and coverage, and recommends purchases.
• The management account sees every account's costs; member accounts see only their own.
• The console is free; the API costs $0.01 per request.

Sources

• AWS Cost Management User Guide: Analyzing your costs and usage with AWS Cost Explorer
• AWS Cost Management User Guide: Filtering the data that you want to view
• AWS Cost Management User Guide: Exploring more data for advanced cost analysis
• AWS Cost Management User Guide: Multi-year data at monthly granularity
• AWS Cost Management User Guide: Forecasting with Cost Explorer
• AWS Cost Management User Guide: Controlling access to Cost Explorer
• AWS Cost Management User Guide: Optimizing your cost with rightsizing recommendations
• AWS Billing User Guide: Organizing and tracking costs using AWS cost allocation tags
• AWS Billing User Guide: Activating user-defined cost allocation tags
• AWS Billing User Guide: Backfill cost allocation tags
• AWS Compute Optimizer User Guide: What is AWS Compute Optimizer?
• AWS Cost Explorer pricing