Find the AWS resources that should be dead but still bill you.

zombiecost is a free, read-only CLI. One scan, one table, a number at the bottom you can act on today.

$ pip install zombiecost
$ zombiecost --profile prod

 Check           Region     Resource                What we found                               Est. $/month
 ec2-idle        eu-west-1  i-0a1b2c3d4e5f67890     m5.large 'batch-worker' averaged 1.2% CPU          70.08
 nat-idle        eu-west-1  nat-0123456789abcdef0   NAT gateway moved 4.1 MiB in 14 days               32.85
 lb-unused       us-east-1  legacy-api              application load balancer has no targets           16.43
 ebs-unattached  eu-west-1  vol-0fedcba9876543210   500 GiB gp2 volume not attached to anything        50.00
 eip-unused      us-east-1  eipalloc-0abc123def45    Elastic IP 54.12.34.56 is not associated            3.65

 Estimated waste: $173.01 per month across 5 resources in 17 regions.

What it checks

• EBS volumes attached to nothing, and snapshots older than 90 days no AMI uses
• Elastic IPs not associated with anything
• EC2 instances under 3% CPU and RDS instances with zero connections
• NAT gateways moving almost no traffic
• Load balancers with no targets, or serving zero requests
• S3 buckets nothing has written to in six months

Built not to annoy you

• Read-only. The IAM policy is eleven Describe, List and Get actions. It is in the README.
• No false alarms on new things. Anything younger than 3 days is skipped.
• Honest about limits. S3 findings say "reads unknown", because reads are invisible without paid request metrics.
• Fast. All regions in parallel, about 9 seconds on an empty account.

Source and IAM policy: github.com/arabo11/zombiecost. MIT licensed.