In the previous subchapter, you learned how to view and control your costs with Cost Explorer and Budgets. Those tools show you the spending, but you have to decide what to optimize. What if AWS gave you specific recommendations on what to change to save and improve? That’s what Trusted Advisor and Compute Optimizer do: two automatic advisors that analyze your account and proactively tell you what to do.

Cost Explorer shows you the numbers; these tools go a step further and recommend actions:

It’s the difference between a dashboard (which shows data) and an advisor (who tells you what to do with it).

AWS Trusted Advisor is like an automatic consultant that reviews your AWS account and gives you recommendations in several categories, not just costs. It analyzes your account and points out opportunities for improvement and issues:

Analogy: Trusted Advisor is like bringing in an expert inspector to review your house who, as they walk through, tells you: “this window doesn’t close properly (security)”, “you have a lightbulb wasting energy (cost)”, “you’re missing a smoke detector here (security/faults)”, “this outlet is overloaded (performance)”. It gives you a clear list of what to fix and why.

• “You have servers with very low usage → consider turning them off or downsizing.”
• “You have reserved IP addresses not in use → you’re being charged for nothing, release them.”
• “You have disks not attached to any server → they’re still costing you, delete them.”
• “You could save by purchasing reserved capacity for these resources” (we’ll cover this in subchapter 25.4).

Each recommendation usually comes with the estimated savings, so you can prioritize.

AWS Compute Optimizer is more specialized: it focuses on recommending the right size for your compute resources (EC2 servers, Lambdas, etc.). It analyzes how you actually use those resources (their CPU, memory, etc., over time, using CloudWatch data) and tells you if they are properly sized, oversized (too big, wasting money), or undersized (too small, running tight).

Analogy: Compute Optimizer is like an advisor who looks at your electricity bill and your habits and tells you: “you have a 10 kW contract but never go above 4; drop to 5 kW and you’ll pay much less without ever falling short.” It looks at your actual usage and adjusts the size to what you really need.

This size adjustment is so important it has its own name —rightsizing— and we dedicate the next entire subchapter (25.3) to it. Compute Optimizer is the tool that gives you those rightsizing recommendations with data.

They complement each other: Trusted Advisor gives you a broad view of improvements in many areas, and Compute Optimizer dives deep into the optimal sizing of your compute resources.

Real-world example: a company has been on AWS for a year without reviewing anything. They activate Trusted Advisor and get a list: 5 unused IPs (charging for nothing), 8 orphaned disks, 3 almost idle servers, and two security alerts. Then they check Compute Optimizer, which tells them half their servers are oversized and could use smaller sizes. By applying the recommendations, they reduce their bill by 35% without affecting service, and also improve their security. All thanks to automatic advisors they just had to look at.

First you see the spending, then you get recommendations, and then you act (starting with rightsizing in the next subchapter).

• Cost Explorer and Budgets show and control spending; Trusted Advisor and Compute Optimizer go a step further and recommend specific actions. It’s moving from a dashboard to an advisor.
• Trusted Advisor is a general automatic consultant that reviews your account and recommends improvements in costs, security, performance, fault tolerance, and limits (with estimated savings). Like an inspector walking through your house pointing out what to fix.
• Compute Optimizer is specialized in recommending the right size for your compute resources based on their actual usage (detects oversized and undersized). Like a contracted power advisor.
• They complement each other: Trusted Advisor gives a broad view, Compute Optimizer dives deep into sizing (rightsizing).
• Applying their recommendations can greatly reduce your bill without affecting service, and also improve security and reliability.

In the next subchapter, we’ll dive deeper into the most direct savings technique these tools recommend: rightsizing (adjusting the size of resources to what you really need).