How to stop an EC2 instance at night to save money (and why it doesn't save anything in Lightsail)

An EC2 machine is billed for the time it is running. A development, testing or office intranet server that is only used during working hours is running 168 hours a week and is used for maybe 50. Stopping it at night and at weekends cuts the compute part of its bill by more than half, without changing anything it does. This guide explains what you really save, what you don't, and how to schedule it so it happens on its own.

At the end we clear up the classic question: what about Lightsail? The short answer is that stopping a Lightsail machine saves nothing, and it is worth knowing why.

Step by step

1. Understand what you stop paying and what you don't

   When you stop an EC2 instance you stop paying for the instance's compute, which is the big part. You keep paying for:

   • The EBS disk, because the data is still there. It is charged per GB per month whether the machine is running or not.
   • The snapshots of that disk.
   • The Elastic IP if you have one associated. AWS charges for public IPv4 addresses, and an Elastic IP assigned to a stopped machine is charged all the same.

   If the machine carries an hourly licence (Windows, some Marketplace images), that part also stops when you stop it.

2. Check that the machine can cope with being stopped

   Before automating anything, test it by hand: stop the instance from the EC2 console and start it again. Check three things: that the services start on their own when it boots (web, database, queues), that the machine keeps the same IP (only if it has an Elastic IP; without one, the public IP changes on every start) and that it doesn't use instance store storage, which is wiped when you stop. If any of this fails, fix it first.

3. Tag the machines that get stopped

   In the EC2 console, select the instance, Tags tab, and add for example Horario = oficina. It is not mandatory, but it lets you see at a glance which machines are part of the shutdown and, if you later use a scheduling tool, select them by tag instead of one by one.

4. Create the shutdown schedule with EventBridge Scheduler

   Open Amazon EventBridge, Scheduler menu, and click Create schedule. Give it a name (apagar-dev-noche), choose Recurring schedule with a cron expression, for example 0 20 ? * MON-FRI * for 20:00 Monday to Friday, and set the time zone to yours (Europe/Madrid) so that daylight saving changes don't throw you off.

   For the target, choose All APIs, search for EC2 and the StopInstances action. In the input box paste the machine's identifier:

   { "InstanceIds": ["i-0123456789abcdef0"] }

   Let EventBridge create a new execution role; it will give it exactly the permission to perform that action. Save.

5. Create the startup schedule

   Repeat the previous step with the name encender-dev-manana, cron 0 7 ? * MON-FRI * and the StartInstances action, with the same identifier. If the machine takes a while to boot and people arrive at 8, set it to 7:30. Better a spare quarter of an hour than complaints.

6. Keep an eye on it the first week

   The next day look at the machine's tab: the "last state transition" should match your hours. In EventBridge Scheduler each schedule shows its last run and whether it failed. After a few weeks you will see the effect in Cost Explorer by filtering on that instance or on the tag.

Why stopping doesn't save money in Lightsail

Lightsail is not billed per hour of use but as a monthly bundle: so much a month for a machine of a certain size, including its disk, its IP and a transfer allowance. That bundle is charged for as long as the machine exists, running or stopped. AWS says so clearly in its documentation: stopped instances are still charged.

If you really want to stop paying for a Lightsail machine you don't use, the way is different: take a snapshot and delete the machine. You will pay only for the snapshot storage, which is much cheaper, and when you need it you create a new machine from it (there is a step-by-step guide in this same section). For a machine used every day during office hours, Lightsail is simply not the tool for saving money by stopping; either you accept the fixed price or you move it to EC2.

What can go wrong