CloudTrail Vs. CloudWatch: A Full Comparison Guide

One tracks what happened, who did it, and when it happened. The other monitors how your systems are performing so you can see why and do something about it. Knowing the difference between CloudTrail vs. CloudWatch isn’t just helpful for engineers. 

It’s essential for finance and leadership teams, too. That’s because the two services can quietly rack up costs in the background.

In this guide, we’ll break down what CloudTrail and CloudWatch do, how they differ, and why it matters to your bottom line. We’ll also share how a cost optimization platform keeps your monitoring costs in check — without sacrificing full visibility.

What Does AWS CloudTrail Do?

CloudTrail logs your AWS activity across one or more accounts. It records who did what, when, and from where across your AWS account. Every time a user, service, or role makes an API call — whether through the console, SDK, or CLI — CloudTrail captures it. This makes it a go-to tool for auditing, compliance, and security investigations.

CloudTrail is particularly suited to doing the following:

Now, here’s how CloudWatch compares. 

What Is AWS CloudWatch?

CloudWatch is AWS’s built-in observability service. It collects and analyzes operational data like logs, metrics, events, and traces from your AWS components.

While CloudTrail focuses on who did what, CloudWatch is all about how your systems are performing. In other words, CloudWatch helps you track the health, performance, and resource utilization of your workloads.

AWS designed CloudWatch for:

Now that we’re clear on what CloudWatch and CloudTrail do, let’s clear up any confusion by breaking down their key differences.

CloudTrail Vs. CloudWatch: A Quick Comparison

In a rush? Here’s a quick side-by-side breakdown of the key differences between CloudTrail vs. CloudWatch.

Table: Differences between CloudWatch vs. CloudTrail 

CloudTrail Vs. CloudWatch: These 3 Areas Make All The Difference

Consider the following.

Auditing vs. performance monitoring

CloudTrail is designed for governance, compliance, and auditing. The service provides a detailed event history of API activity and user action changes for accountability and security tracking. For instance, if an EC2 instance is unexpectedly terminated, CloudTrail can help you identify who initiated the termination and when.

CloudWatch, on the other hand, focuses on performance monitoring and operational efficiency. It tracks resource metrics such as CPU usage, memory, and network activity, offering real-time insights into system health. For example, you can set up an alarm to notify you when CPU usage exceeds 85% on an EC2 instance.

Data type, granularity, and analytics

CloudTrail captures detailed logs of API activity, recorded as events. Each event includes granular data such as the source IP address, request parameters, and response elements.

By default, CloudTrail stores this event history in Amazon S3 for 90 days (configurable to 10 years). For deeper analysis, CloudTrail Lake enables you to aggregate, immutably store, and run SQL queries across activity logs from various sources — all in one place.

You can also filter events by specific attributes like API actions or timestamps — especially useful for security and compliance audits.

CloudWatch aggregates performance metrics, logs, events, and traces about every five minutes (configurable to 1 minute). It retains this data for 15 days by default.

It collects built-in metrics from over 70 AWS services — and even from external sources like on-premises environments. 

You can also define custom metrics to monitor, understand, and optimize system performance your way. 

By combining custom metrics with agents or APIs, you can collect near-real-time performance insights. CloudWatch retains this data for up to 15 months, making it useful for trend analysis and historical reporting. 

For long-term storage, you can export the data to Amazon S3 using Amazon Athena.

Pricing differences between CloudTrail vs. CloudWatch

Like most AWS services, both follow a usage-based pricing model.

CloudTrail uses tiered pricing for event history and advanced analytics, while CloudWatch offers granular charges for metrics, logs, and dashboards. Both services offer free tiers for basic usage but scale costs based on the resources you consume and the specific features you choose.

We’ve covered the pricing details for each service. See the deeper dives here:

To wrap it up, CloudTrail and CloudWatch are powerful on their own. They work even better together. 

One helps you monitor the health and performance of your systems. The other gives you a clear, traceable audit of everything happening across your AWS account.

But here’s what most teams don’t realize, until it’s too late. 

CloudTrail and CloudWatch can quietly become two of your biggest cloud cost line items. This is especially so in fast-growing environments with limited cost visibility and multiple teams accessing resources. 

Here’s what to do.

Understand, Control, And Optimize Your Monitoring Costs Without Sacrificing Full Observability

You could try to untangle this mess with AWS Cost Explorer. But good luck answering questions like:

If getting accurate, data-backed answers to such questions would help protect your margins, then CloudZero is built for you.

With CloudZero, you get real-time, context-rich cloud cost intelligence mapped directly to the people, products, and processes driving your AWS spend. So you’re never in the dark about what’s changing, why it’s happening, or how to fix it.

From cost per customer, team, deployment, and feature, CloudZero delivers the actionable insights your engineering, finance, and leadership teams need to make profitable decisions — all without sacrificing full visibility.

Join innovative teams from Skyscanner, Duolingo, Remitly, Drift, and more, who already use and trust CloudZero to take control of their cloud costs. to start seeing why.

CloudWatch Vs. CloudTrail FAQs

What is the difference between CloudTrail and CloudWatch?

The biggest difference is that CloudTrail logs API and user activity across your AWS accounts for governance, security, and compliance purposes. Meanwhile, CloudWatch collects and monitors metrics, logs, traces, and events from your AWS environment components for tracking the health, performance, and utilization of your resources. 

Together, they provide a full picture of what happened and how your systems responded.

Can CloudWatch replace CloudTrail?

CloudTrail and CloudWatch are complementary services, not alternatives. Combining them gives you deeper troubleshooting and monitoring capabilities. Think of understanding how a configuration change (logged in CloudTrail) impacted system performance (monitored in CloudWatch) and exactly how much that change is costing you per hour (insights you’ll uncover with CloudZero).

Does CloudZero integrate with CloudTrail and CloudWatch?

Yes. CloudZero ingests and enriches data from both services, then breaks it down into actionable, context-rich cost insights. You’ll be able to see which services, teams, environments, or features are driving CloudTrail and CloudWatch costs — and take action before those costs spiral out of control.

Author: Cody Slingerland

Cody Slingerland, a FinOps certified practitioner, is an avid content creator with over 10 years of experience creating content for SaaS and technology companies. Cody collaborates with internal team members and subject matter experts to create expert-written content on the CloudZero blog.