Switch an EC2 instance from on-demand to spot pricing

It's not currently possible to convert an Amazon EC2 on-demand instance to a spot instance.

You can save your instance as an AMI and then use the AMI as the source for an instance launched as spot instance.

Hi,

The following tool will automate the process of converting an EC2 on-demand instance to Spot billing model:
https://github.com/jcjorel/ec2-spot-converter

Best.

“This tool converts existing AWS EC2 instances back and forth between On-Demand and 'persistent' Spot billing models while preserving instance attributes (Launch configuration, Tags..), network attributes (existing Private IP addresses, Elastic IP), storage (Volumes), Elastic Inference accelerators, Elastic GPUs.

Others features:

• Can also perform Spot-to-Spot and OnDemand-to-OnDemand conversions:
• Allow replacement of existing Spot instances with new "identical" ones to update the instance type and CPU options,
• Help to fix some Spot instance conditions (Ex: 'IncorrectSpotRequestState Exception'),
• Allow Root Disk encryption during conversion. Can preserve ELB Target Group instance registrations (disabled by default),
• Can update existing CloudWatch alarms referring the converted Instance Id (disabled by default)”