# Create a change set for a CloudFormation stack
<a name="using-cfn-updating-stacks-changesets-create"></a>

To create a change set for a running stack, submit the changes that you want to make by providing a modified template, new input parameter values, or both. CloudFormation generates a change set by comparing your stack with the changes you submitted.

You can either modify a template before creating the change set or during change set creation.

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#### [ Create a change set (console) ]

**To create a change set**

1. Open the CloudFormation console at [https://console.aws.amazon.com/cloudformation](https://console.aws.amazon.com/cloudformation/).

1. On the navigation bar at the top of the screen, choose your AWS Region.

1. On the **Stacks** page, choose the running stack you want to create a change set for.

1. In the stack details pane, choose **Stack actions**, and then choose **Create a change set**.

1. On the **Create change set for {{stack-name}}** page, do one of the following to modify input parameter values, specify the location of an updated template, or modify the template:    
[See the AWS documentation website for more details](http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-changesets-create.html)

1. On the **Specify stack details** page, specify a name for the change set and optionally specify a description of the change set to identify its purpose in the **Overview** section. If your template contains parameters, on the **Specify stack details** page, enter or modify applicable input parameter values, and then choose **Next**.

   If you're reusing the stack's template, CloudFormation populates each parameter with the current value in the stack, with the exception of parameters declared with the `NoEcho` attribute. To use existing values for those parameters, select **Use existing value**.

   For more information about using `NoEcho` to mask sensitive information, and using dynamic parameters to manage secrets, see the [Do not embed credentials in your templates](security-best-practices.md#creds) best practice.

1. On the **Configure stack options** page, update the stack's tags, IAM service role, stack policy, rollback configuration, Amazon SNS notification topic (if applicable), or change sets.
**Note**  
Change sets for nested stacks are **Enabled** by default, which will create change sets for all nested stacks specified in your template. To create a change set for the current stack only, choose **Disabled**. For more information about change sets for nested stacks, see [Change sets for nested stacks](change-sets-for-nested-stacks.md).

1. If the template includes IAM resources, for **Capabilities**, choose **I acknowledge that CloudFormation might create IAM resources**. IAM resources can modify permissions in your AWS account; review these resources to ensure that you're permitting only the actions that you intend. For more information, see [Acknowledging IAM resources in CloudFormation templates](control-access-with-iam.md#using-iam-capabilities).

1. Choose **Next** to continue.

1. On the **Review {{stack-name}}** page, review the changes for this change set.

1. Choose **Submit**.

   You're redirected to the **Changes** tab of the change set's details page. While CloudFormation generates the change set, the status of the change set is `CREATE_PENDING`. After it has created the change set, CloudFormation sets the status to `CREATE_COMPLETE`. In the **Changes** section, CloudFormation lists all of the changes that it will make to your stack. For more information, see [View a change set for a CloudFormation stack](using-cfn-updating-stacks-changesets-view.md).

   Choose **View details** in the **Property-level changes** column to view changes made at the property-level.

   If CloudFormation fails to create the change set (reports `FAILED` status), fix the error displayed in the **Status** field, and then recreate the change set.

1. After confirming the changes look correct, choose **Execute change set**

------
#### [ Create a change set for nested stacks (console) ]

**To create a change set for nested stacks**

1. Open the CloudFormation console at [https://console.aws.amazon.com/cloudformation](https://console.aws.amazon.com/cloudformation/).

1. On the navigation bar at the top of the screen, choose your AWS Region.

1. On the **Stacks** page, select the running stack you want to create a change set for.

1. In the stack details pane, choose **Stack actions**, and then choose **Create a change set**.

1. On the **Create change set for {{stack-name}}** page, do one of the following to modify input parameter values, specify the location of an updated template, or modify the template:    
[See the AWS documentation website for more details](http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-changesets-create.html)

1. On the **Specify stack details** page, specify a name for the change set and optionally specify a description of the change set to identify its purpose in the **Overview** section. If your template contains parameters, on the **Specify stack details** page, enter or modify applicable input parameter values, and then choose **Next**.

   If you're reusing the stack's template, CloudFormation populates each parameter with the current value in the stack, with the exception of parameters declared with the `NoEcho` attribute. To use existing values for those parameters, select **Use existing value**.

   For more information about using `NoEcho` to mask sensitive information, as well as using dynamic parameters to manage secrets, see the [Do not embed credentials in your templates](security-best-practices.md#creds) best practice.

1. On the **Configure stack options** page, update the stack's tags, IAM service role, stack policy, rollback configuration, Amazon SNS notification topic (if applicable), or change sets. For more information, see [Configure stack options](cfn-console-create-stack.md#configure-stack-options).
**Note**  
Change sets for nested stacks are **Enabled** by default, which will create change sets for all nested stacks specified in your template. For more information about change sets for nested stacks, see [Change sets for nested stacks](change-sets-for-nested-stacks.md).

1. If the template includes IAM resources, for **Capabilities**, choose **I acknowledge that CloudFormation might create IAM resources**. IAM resources can modify permissions in your AWS account; review these resources to ensure that you're permitting only the actions that you intend. For more information, see [Acknowledging IAM resources in CloudFormation templates](control-access-with-iam.md#using-iam-capabilities).

1. Choose **Next** to continue.

1. On the **Review {{stack-name}}** page, review the changes for this change set.

1. Choose **Submit**.
**Note**  
CloudFormation property-level change sets does not resolve cross-stack references when you create change sets for nested stacks. Change sets can mark resources in a child stack for conditional replacement if they reference the output of a parent stack, and the parent stack has been modified

   You're redirected to the **Changes** tab of the change set's details page. While CloudFormation generates the change set, the status of the change set is `CREATE_PENDING`. After it has created the change set, CloudFormation sets the status to `CREATE_COMPLETE`. In the **Changes** section, CloudFormation lists all of the changes that it will make to your stack. For more information, see [View a change set for a CloudFormation stack](using-cfn-updating-stacks-changesets-view.md).

   If CloudFormation fails to create the change set (reports `FAILED` status), fix the error displayed in the **Status** field, and then recreate the change set.

1. After confirming the changes look correct, choose **Execute change set**

------

**To create a change set (AWS CLI)**
+ Use the [create-change-set](https://docs.aws.amazon.com/cli/latest/reference/cloudformation/create-change-set.html) command.

  You submit your changes as command options. You can specify new parameter values, a modified template, or both. For example, the following command creates a change set named `SampleChangeSet` for the `MyStack` stack. The change set uses the current stack's template, but with a different value for the `Purpose` parameter:

  ```
  aws cloudformation create-change-set --stack-name {{MyStack}} \
      --change-set-name {{SampleChangeSet}} --use-previous-template \
      --parameters \
        {{ParameterKey="InstanceType",UsePreviousValue=true ParameterKey="KeyPairName",UsePreviousValue=true ParameterKey="Purpose",ParameterValue="production"}}
  ```

**Note**  
In addition to property syntax validation and resource name conflict detection, change set creation checks for service quota limits, Recorder conflicts, and ECR repository delete readiness. These checks operate in WARN mode – CloudFormation creates the change set successfully, but warnings indicate potential issues. We recommend that you address these issues before you execute the change set.

**Express mode**  
To create a change set that uses express mode, add the `--deployment-config` parameter:

```
aws cloudformation create-change-set --stack-name {{MyStack}} \
    --change-set-name {{MyExpressChangeSet}} \
    --use-previous-template \
    --deployment-config '{"mode": "EXPRESS"}'
```

When you execute this change set, CloudFormation uses express mode, completing resource operations as soon as configuration is applied. For more information, see [Express mode](cloudformation-express-mode.md).