Unused AMIs keeping EBS snapshots

What LeftSize checks

Find AMIs owned by this account that are at least 90 days old and not used by any EC2 instance or Auto Scaling group (launch configuration or launch template). Each AMI keeps its EBS snapshots, billed at about $0.05/GB-month, until it is deregistered and the snapshots are deleted. Skips AMIs shared with other accounts or public, and AMIs managed by AWS Backup or Data Lifecycle Manager. Launch templates not attached to an ASG (Batch, EC2/Spot Fleet, Karpenter, scripts) aren't checked; the issue tells users how to verify.

Why it matters

Resources like this keep billing every hour while delivering little or no value, and nobody notices until the invoice arrives.

What you get in the GitHub issue

LeftSize runs this check from a scheduled GitHub Action with a read-only identity in your AWS account and opens one issue per scope, updated on every scan. The issue includes:

• The affected resources, grouped per subscription, resource group or account and region
• An estimated monthly cost where pricing data is available
• Background on why it was flagged and when it is a false positive
• Step-by-step remediation with safety checks
• Ready-to-run fix scripts (CLI, PowerShell or Terraform where available)
• Cost and operational impact of fixing it
• Alternative approaches and their trade-offs
• Snooze, ignore or report a finding with a comment on the issue