If your subscription Elastic Compute Service (ECS) instance is overprovisioned or insufficient for your workload, you can change its instance type, which includes its vCPU and memory. You can upgrade to a higher-priced instance type or downgrade to a lower-priced one.
Prerequisites
The current instance family supports instance type changes. For more information, see Limitations and pre-checks for changing instance types.
The instance is in the Running or Stopped state.
The target instance type is in stock in the current zone. You can check the inventory status at Instance Types Available for Each Region page.
Note- Important
If you want to migrate your ECS instance to another region, we recommend the following solutions:
Utilize the server migration feature to migrate your ECS instance from one region to another. For more information, see Migrate ECS instances between different accounts or within the same account.
Create a custom image of your current instance, copy the custom image to the destination region, and use this custom image to create an instance there. For more information, see Create a custom image from an instance, Copy a custom image, and Create an instance from custom image or shared image.
Limitations
The following limitations apply:
You must specify a target instance type (both vCPU and memory). You cannot change only one.
You can only change the instance type for the current billing cycle. Temporary changes are not supported.
You cannot change the instance type if another configuration change, such as changing the instance type, modifying bandwidth, or a temporary bandwidth upgrade, is in progress for the instance.
If you have renewed a subscription instance to a lower-tier type for the next billing cycle, you cannot upgrade the instance until that new cycle begins.
You cannot downgrade a subscription instance if a renewal to a lower-tier type is already pending. You must wait for the renewal process to complete first.
Downgrades are subject to a monthly quota based on your historical consumption. The specific limit is shown on the page, and you cannot perform further downgrades once you exceed it. The quota is automatically reset on the first day of the next month.
Billing
When you upgrade, you must pay an upgrade fee.
Upgrade fee = (List price of the new instance type for the remaining billing cycle - List price of the original instance type for the remaining billing cycle) × Discount for the remaining billing cycle
When you downgrade, you may receive a refund. The refund amount is the difference between the price of the new configuration and the remaining value of the original purchase. For more information, see Rules for unsubscribing from resources.
If the instance is part of a long-term promotional campaign, changing its configuration may disqualify you from the promotional price at renewal.
Procedure
Changing the instance type requires you to restart the ECS instance. Perform this operation during off-peak hours to minimize business impact.
Go to ECS console - Instances.
In the top navigation bar, select the region and resource group of the resource that you want to manage.
Click the ID of the target subscription instance to go to its details page. In the upper-right corner of the page, choose All Actions > Upgrade/Downgrade > Change Instance Type.
NoteYou can perform batch operations on the Instance page to change the instance types of multiple instances at a time. On the Instance page, select multiple instances and choose at the bottom of the page, and follow the on-screen instructions.
Select a target instance type.
NoteThe available instance types are subject to the information displayed on the page.
Change the instance type.
Upgrade the instance type
The steps vary based on the current state of the instance.
The instance is Stopped:
Confirm the estimated cost, select Read and select ECS Terms of Service, and then click Confirm Change and Pay.

Follow the on-screen instructions to complete the payment.
To apply the change, start the instance.
After payment is complete, the console displays the new instance type, but the change has not yet taken effect. To make the change effective, start the instance.
The instance is Running:
Set the restart time.
If you select Scheduled Instance Restart Time for Instance Restart Mode and specify a restart time, you can view or modify the specified time under .
WarningRestarting an instance causes it to stop, which may interrupt your services. Perform this operation during off-peak hours.
For some instance types, you may see a message like "no timed execution. cannot scheduled downgrade". This means the instance does not support scheduled restarts and must be stopped before its type can be changed.
After confirming the changes, select Read and select ECS Terms of Service, and then click Confirm Change and Pay or Confirm Change and Restart Instances.
Restart the instance.
After you click Confirm Change and Pay and complete the payment, the ECS console displays the new instance type, but the change does not take effect until you restart the instance.
Downgrade the instance type
The steps vary based on the current state of the instance.
The instance is Stopped: Confirm the changes, select Read and select ECS Terms of Service, and then click Confirm Change.

The instance is Running:
Confirm the changes, select Read and select ECS Terms of Service, and then click Stop Instances and Proceed.
In the Stop Instance dialog box, select a stop method under Stopped By and click Confirm.

To apply the instance type change, start the instance.
For instructions, see Start an instance.
References
DescribeResourcesModification: Queries available resources in a zone for an instance type or system disk upgrade or downgrade.
ModifyInstanceSpec: Adjusts the instance type and public bandwidth of a pay-as-you-go ECS instance.
DescribeInstanceModificationPrice: Queries the price of upgrading an active subscription ECS instance to a new instance type, including new data disks.