Spot instances let you bid on spare Amazon EC2 instances to name your own price for compute capacity. The Spot price fluctuates based on the supply and demand of available EC2 capacity. Your Spot instance is launched when your bid exceeds the current Spot market price, and will continue run until you choose to terminate it, or until the Spot market price exceeds your bid. You are charged the Spot market price (not your bid price) for as long as the Spot instance runs. If the Spot market price increases above your bid price, your instance will be terminated automatically and you will not be charged for the partial hour that your instance has run. With Spot instances, you will never be charged more than the price you bid.
If you include a duration requirement with your Spot instances request, your instance will continue to run until you choose to terminate it, or until the specified duration has ended; your instance will not be terminated due to changes in the Spot price.
Spot prices are set by Amazon EC2 and fluctuate periodically depending on the supply of and demand for Spot instance capacity. Spot instances are also available to run for a predefined duration – in hourly increments up to six hours in length – at a significant discount (30-45%) compared to On-Demand pricing plus an additional 5% during off-peak times1 for a total of up to 50% savings.
The following table displays the Spot price per region and instance type (updated every 5 minutes), as well as the price for Spot instances available for predefined durations. To learn more about pricing, visit the AWS pricing and Amazon EC2 pricing page, or get started today.