AWS cost monitoring

Catch AWS overspend before the invoice does

CostMon connects to AWS Cost Explorer and turns your raw billing data into a daily, normalized view that finance and engineering both trust. A runaway service gets caught within days, while it's still cheap to fix.

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AWS Cost Explorer, live today

AWS Cost Explorer shows you spend. It doesn't show urgency. It's built for monthly review, so it never flags a forgotten NAT gateway or an idle GPU fleet while the fix is still cheap. A cost anomaly reaches the invoice weeks after it started, and by then the spend is already sunk. Finance sees a lagging number. Engineering has no daily signal to act on.

Cost anatomy

What actually drives your AWS bill

NAT Gateway, hourly plus per-GB: A NAT Gateway bills an hourly charge plus a per-GB data-processing fee on every byte that passes through it. A forgotten one in a rarely used VPC still accrues the hourly charge every single hour, whether or not anything is using it.
EBS volumes bill whether attached or not: An EBS volume keeps billing by the GB-month regardless of whether an instance is using it. Stopping or terminating an instance doesn't stop its orphaned volumes from billing.
On-Demand vs. Savings Plan coverage: On-Demand compute costs several times more per hour than the same instance covered by a Savings Plan or Reserved Instance. A coverage gap from autoscaling past a commitment, or a commitment that's lapsed, reverts spend to the higher rate without anyone changing a setting.
Cross-AZ and egress data transfer: Data transfer between Availability Zones, and out to the internet, bills per GB on its own meter, separate from compute and storage. Traffic volume sets the charge. The console shows no line for it.

Alerts

How CostMon warns you about AWS spend

CostMon's default rule watches every service on your account from the day you connect it. An alert always shows up in your CostMon feed. Add an email, Slack, or webhook channel to send it somewhere else too.

Anomaly rulesource = aws, service = EC2 - Other

A NAT Gateway suddenly processing far more traffic, which lifts the EC2 - Other line past its normal range.

Anomaly rulesource = aws, service = Amazon Elastic Compute Cloud - Compute

A GPU fleet launched for a test and left running, holding compute spend well above its baseline.

Budgetsource = aws

A monthly budget on total AWS spend fires when the month passes your limit. A lapsed Savings Plan is one cause, because usage reverts to On-Demand rates.

Sample alert, illustrative

From: alerts@costmon.com
Subject: CostMon alert: Anomaly: aws / EC2 - Other spend spike

Anomaly: aws / EC2 - Other spend spike

aws / EC2 - Other was $315.00 on 2026-07-14 — 75% above its 14-day average of $180.00.

Severity: warning
Occurred on: 2026-07-14

To find what to cut, the recommendations list flags idle spend and commitment gaps to review.

Why CostMon

Built for AWS spend, from day one

Daily sync beats monthly review

CostMon pulls AWS Cost Explorer data on a schedule. You get a daily total instead of an end-of-month report. A climbing line is visible while you can still act.

Runaway spend shows as a rising line

CostMon stores spend by service and linked account. A jump in one service points you to the area to check. Then you look for the cause in the AWS console.

One number for finance and engineering

Stop reconciling Cost Explorer exports against a spreadsheet. Everyone looks at the same normalized total, broken down the same way, refreshed on the same schedule.

Read-only, Cost Explorer-scoped credentials

CostMon connects with AWS credentials scoped to Cost Explorer billing data only. Those credentials cannot start, stop, or change a single resource.

HourlyNAT Gateway bills every hour, even when idle
~16 daysearlier than the invoice
Cost ExplorerAWS Cost Explorer pull, daily

Getting started

From API key to first alert, for AWS

01
Connect AWS Cost Explorer
Add a read-only, cost-scoped AWS role in a few minutes. CostMon never touches your workloads, only billing data.
02
CostMon syncs and normalizes
Cost Explorer data is pulled on a schedule and reconciled into the same normalized model as every other provider you connect.
03
See the line, then get the alert
Open a daily view of AWS spend by service and account. When a NAT Gateway floods the EC2 - Other line, a rule fires.

FAQ

Common questions about the AWS connector

How does CostMon connect to AWS?

Through a read-only AWS Cost Explorer connector, scoped to billing data only. CostMon never requests access to your workloads, source code, or production infrastructure.

Does CostMon replace AWS Cost Explorer?

No. CostMon reads from Cost Explorer. Your AWS bill then sits beside Anthropic, OpenAI, Amazon Bedrock and any other source you add. One dashboard shows every source by day.

How often does AWS cost data sync?

CostMon's background scheduler syncs AWS Cost Explorer data on a regular cadence, so the dashboard reflects a daily view instead of a monthly snapshot.

Can I see AWS costs broken down by service or account?

Yes. CostMon records the service and linked account for every AWS row. Trends split by provider or by service. For team totals, write an allocation rule that matches the source, the service or the connector.

What does the AWS connector cost?

A flat monthly rate per plan. It never charges a percentage of your AWS bill or the savings CostMon helps you find. Free includes 2 connectors; Professional and Enterprise include unlimited connectors.

Connectors

Cloud, AI, and SaaS: all in one place

AWS, GCP, and Azure for cloud. Anthropic, OpenAI, Amazon Bedrock, Vertex AI / Gemini, and Helicone for AI and LLM spend. Snowflake and Databricks for the data cloud. Datadog, GitHub, and Vercel for the rest of the stack. Add CSV import for any tool without a native connector. That's 14 connectors, all normalized into the same unified view.

Connect it. Get the first alert.

Connect a provider and CostMon builds a daily baseline for it. From there, a spike reaches your team as an alert.

Start free See how to connect a provider