AWS Cloud9: What It Is and When to Use It

IMPORTANT NOTE: As of July 25, 2024, AWS Cloud9 is no longer available to new customers. Existing customers can continue to use the service, and AWS will continue to provide security, availability, and performance improvements, but no new features are planned. This article is for existing users and certification candidates who may still encounter questions about the service.

Definition

AWS Cloud9 is a cloud-based Integrated Development Environment (IDE) that lets you write, run, and debug code using just a web browser. It provides a fully-featured code editor, a debugger, and a terminal, solving the problem of inconsistent local development environments and the need to install and configure tools on individual developer machines.

How It Works

AWS Cloud9 works by providing a web-based IDE that connects to a backend computing environment where your code is stored and executed. This environment can be one of two types:

EC2 Environment: When you create this type of environment, AWS Cloud9 automatically provisions a new Amazon Elastic Compute Cloud (EC2) instance to host your development workspace. The IDE connects directly to this managed instance. This is the most common setup, as it comes pre-configured with the AWS Command Line Interface (CLI), popular SDKs, and other essential tools.
SSH Environment: This option allows you to connect AWS Cloud9 to an existing Linux-based server, which could be an EC2 instance, an on-premises server, or a virtual machine from another cloud provider. The server must meet specific requirements, such as running a supported Linux distribution and being accessible over the public internet via SSH.

In both cases, the developer interacts with the IDE in their browser. The IDE includes a file explorer, code editor panes, and a powerful terminal with sudo privileges to the underlying instance. This allows for a seamless development experience without being tied to a specific physical machine.

Key Features and Limits

Key Features

Cloud-Based IDE: Access a consistent, powerful development environment from any internet-connected machine with a modern browser.
Fully-Featured Editor: Includes code completion, hinting, syntax highlighting, and customizable layouts with drag-and-drop panels.
Integrated Debugger: Provides common debugging capabilities like setting breakpoints, stepping through code, and inspecting variables for languages like JavaScript (Node.js), Python, PHP, and C++.
Built-in Terminal: A full-featured terminal with sudo access to the underlying EC2 instance and a pre-authenticated AWS CLI.
Real-Time Collaboration: Share your environment with team members for pair programming. Multiple users can see each other's cursors, type in the same file simultaneously, and communicate via a built-in chat feature.
Serverless Development Tools: Integrated experience for developing AWS Lambda functions and serverless applications using the AWS Serverless Application Model (SAM).
Broad Language Support: Supports over 40 programming languages, including Python, JavaScript, PHP, Ruby, Go, and C++.
Cost-Saving Hibernation: EC2 environments automatically stop the underlying instance after a configurable period of inactivity (default is 30 minutes) to save on compute costs.

Service Limits (Quotas)

Environments per Account: 200 (100 per user).
Environments per User: 100 EC2 environments and 100 SSH environments.
Members per Environment: Up to 25 members. The default maximum is calculated based on the instance's memory.
Editable File Size: 8 MB.

These limits are per AWS Region and some can be increased upon request via AWS Support.

Common Use Cases

Serverless Application Development: With built-in tools for AWS Lambda and AWS SAM, Cloud9 is ideal for creating, debugging, and deploying serverless applications.
Collaborative Coding and Pair Programming: The real-time sharing features make it an excellent choice for teams that need to collaborate on code, conduct code reviews, or onboard new developers.
Standardized Development Environments: Teams can ensure every developer works with the same set of tools, dependencies, and configurations, eliminating "it works on my machine" issues.
Quick-Start Development: Because the environment is pre-configured with the AWS CLI, SDKs, and Git, developers can start coding on new projects immediately without lengthy setup times.
Learning and Experimenting with AWS: The pre-authenticated AWS CLI in the terminal provides a safe and easy way for developers new to AWS to explore and interact with various services.

Pricing Model

There is no additional charge for the AWS Cloud9 service itself. Customers pay only for the underlying AWS resources consumed by their development environments.

EC2 Environments: You are billed for the Amazon EC2 instance and the attached Amazon Elastic Block Store (EBS) volume. The cost depends on the instance type (e.g., t2.micro, t3.small) and the size of the EBS volume. The auto-hibernation feature significantly helps in managing costs by stopping the EC2 instance when the IDE is not in use.
SSH Environments: If you connect Cloud9 to an existing server (on-premises or in another cloud), there are no AWS charges from Cloud9. You are responsible for the costs of that server with its provider.
AWS Free Tier: New AWS customers may be able to use AWS Cloud9 for free if their usage of the underlying EC2 and EBS resources falls within the AWS Free Tier limits.

For detailed estimates, use the AWS Pricing Calculator.

Pros and Cons

Pros

Zero Local Setup: Eliminates the need to install and configure IDEs, SDKs, and dependencies on local machines.
Accessibility: Access your full development environment from any computer with a web browser.
Deep AWS Integration: Pre-configured AWS CLI and seamless tools for serverless development streamline AWS workflows.
Enhanced Collaboration: Real-time pair programming and chat features improve team productivity.
Cost-Effective: The pay-for-what-you-use model for underlying resources, combined with auto-hibernation, can be very cost-effective.

Cons

Internet Dependency: Requires a stable internet connection to access the IDE.
Limited Customization: While configurable, it may not offer the same level of deep customization and plugin support as powerful local IDEs like VS Code.
No New Feature Development: As the service is closed to new customers, AWS is no longer planning to introduce new features.
Potential for Latency: Since the IDE is running in the cloud, there can be minor latency compared to a local editor, especially on slow connections.

Comparison with Alternatives

AWS Cloud9 vs. Local IDE (e.g., VS Code with AWS Toolkit): A local IDE like Visual Studio Code offers superior performance, offline access, and a vast ecosystem of extensions. However, it requires local setup and maintenance. The AWS Toolkit for VS Code bridges some of the gap by providing AWS service integration, but Cloud9's strength lies in its fully managed, collaborative, and standardized cloud environment.
AWS Cloud9 vs. AWS CloudShell: AWS CloudShell is a browser-based shell, not a full IDE. It's excellent for quickly running AWS CLI commands or simple scripts directly from the AWS Management Console at no extra cost. Cloud9 is a complete development environment for writing, running, and debugging complex applications.
AWS Cloud9 vs. GitHub Codespaces: GitHub Codespaces is a very similar product, offering a cloud-based development environment (often based on VS Code) that runs in a container. Codespaces is tightly integrated with GitHub repositories and has become a popular alternative, especially since Cloud9 is no longer available for new customers.

Exam Relevance

AWS Cloud9 is a relevant topic for several AWS certifications, particularly those focused on development and architecture.

AWS Certified Developer - Associate (DVA-C02): Candidates should understand how Cloud9 can be used to write, debug, and deploy applications, especially serverless ones using Lambda and SAM. Knowledge of its collaborative features and integration with other AWS services is beneficial.
AWS Certified Solutions Architect - Associate (SAA-C03): Architects should know when to recommend Cloud9 as part of a development workflow solution. This includes understanding its benefits for standardizing environments, improving team collaboration, and accelerating development on AWS.

Examinees are typically expected to know what Cloud9 is, its primary use cases, its pricing model (paying for underlying resources), and how it differs from other tools like CloudShell.

Frequently Asked Questions

Q: Can I connect AWS Cloud9 to my existing on-premises server?

A: Yes, you can. By creating an "SSH environment," you can connect the AWS Cloud9 IDE to any existing Linux server that is accessible from the public internet and meets the necessary host requirements, which include having specific versions of Python and Node.js installed.

Q: How does AWS Cloud9 handle security?

A: Security in AWS Cloud9 follows the AWS Shared Responsibility Model. AWS is responsible for the security of the cloud (the underlying infrastructure), while you are responsible for security in the cloud. This includes managing access using AWS Identity and Access Management (IAM), securing your code (e.g., using AWS CodeCommit), encrypting Amazon EBS volumes for EC2 environments, and never putting sensitive information like credentials into your code.

Q: What is the difference between AWS Cloud9 and AWS CloudShell?

A: AWS Cloud9 is a full-featured, cloud-based Integrated Development Environment (IDE) for writing, running, and debugging code, which runs on a dedicated EC2 instance or a connected server. AWS CloudShell is a simpler, browser-based command-line shell available directly in the AWS Management Console for quick administrative tasks and running scripts, and it is provided at no additional cost.

This article reflects AWS features and pricing as of 2026. AWS services evolve rapidly — always verify against the official AWS documentation before making production decisions.