Last updated June 04, 2024

Heroku offers a variety of dyno types to support apps of all sizes, from small-scale projects to high-traffic production services.

Memory, CPU share, and other differentiating characteristics for each dyno type are listed below:

These figures show expected performance based on 99 percent of historical system loads. The performance of apps running on eco, basic, and standard dyno types can vary based on available system resources, as well as limits in your account. Your app’s performance can also vary significantly based on its implementation.

Heroku prorates costs to the second. You can scale down your dynos when they’re not in use. For information about pricing, see Usage & Billing.

Using eco dynos requires a subscription to Eco. Your usage is tracked to the second and consumes from a pool of 1000 dyno hours shared by all eco dynos in your account. See Eco Dyno Hours for more info.

Dyno Feature Support

Default Scaling Limits

The following limits exist per app:

• By default, applications are limited to 100 total dynos across all process types.
• Apps running on eco or basic dynos can have only one dyno running per process type.
• Apps running on eco dynos are limited to a maximum of two concurrently running dynos. For example, you can have one dyno running for your web process, and one dyno running for worker.
• A single process type that uses performance, private, or shield dynos can’t be scaled to more than 10 dynos.

Submit a request to raise this limit for your application.

Concurrent One-Off Dyno Limits

• 1 Eco one-off dyno (Eco requires a subscription to the Eco dynos plan)
• Up to 50 concurrent one-off Basic dynos
• Up to 50 concurrent one-off Standard-1X dynos
• Up to 50 concurrent one-off Standard-2X dynos
• Up to 5 concurrent one-off Performance-M dynos
• Up to 5 concurrent one-off Performance-L dynos
• Up to 5 concurrent one-off Performance-L-RAM dynos
• Up to 5 concurrent one-off Performance-XL dynos
• Up to 5 concurrent one-off Performance-2XL dynos
• Up to 5 concurrent one-off Private-S dynos
• Up to 5 concurrent one-off Private-M dynos
• Up to 5 concurrent one-off Private-L dynos
• Up to 5 concurrent one-off Private-L-RAM dynos
• Up to 5 concurrent one-off Private-XL dynos
• Up to 5 concurrent one-off Private-2XL dynos
• Up to 5 concurrent one-off Shield-S dynos
• Up to 5 concurrent one-off Shield-M dynos
• Up to 5 concurrent one-off Shield-L dynos
• Up to 5 concurrent one-off Shield-L-RAM dynos
• Up to 5 concurrent one-off Shield-XL dynos
• Up to 5 concurrent one-off Shield-2XL dynos

Submit a request to raise this limit for your application.

Dyno Tiers and Mixing Dyno Types

Dyno types are classified into different tiers.

• Eco tier: An app that uses eco dynos can only use eco dynos for all of its process types.
• Basic tier: An app that uses basic dynos can only use basic dynos for all of its process types.
• Professional tier: An app that uses Professional-tier dynos (standard and performance) can use different Professional-tier dyno types for its processes. For example, an app can run its web process type on performance-m dynos while running workers on standard-1x dynos.

Setting Dyno Types

Setting a new dyno type for a process restarts all affected dynos. If you’re resizing to a larger dyno type, check if you can scale down the number of dynos to optimize resource costs and consumption. See Optimizing Dyno Usage for guidance.

From the Heroku Dashboard

Change the Dyno Tier on Your App

You can choose your app’s dyno tier from the app’s Resources tab on the Heroku Dashboard:

1. Click the app you want to modify from your apps list.
2. Click the app’s Resources tab.
3. Above your list of dynos, click Change Dyno Type.
4. Choose the dyno tier to switch to: Eco, Basic, or Professional (Standard/Performance).
5. Click Save.

Change the Dyno Type of Professional-Tier Dynos

To change between dyno types in the Professional tier:

1. Complete the steps in the previous section to ensure the current dyno tier is set to Standard/Performance.
2. Click the hexagon shape next to the process type you want to resize.
3. Choose an option from the drop-down menu: Standard-1X, Standard-2X, Performance-M, or Performance-L.
4. Click Confirm.

Scale the Number of Dynos

You can scale Professional-tier dynos from the Heroku Dashboard.

From the Heroku CLI

You can use the Heroku CLI to scale or resize the dynos for any process type.

Scale the Number of Dynos

The following command scales the number of web dynos to 3 and preserves the current dyno type.

$ heroku ps:scale web=3

Change the Dyno Type of a Process

The following command changes the worker dyno type to standard-2x and preserves the current number of dynos:

$ heroku ps:type worker=standard-2x

Change the Dyno Type for All Processes

The following command changes the dyno type for all of an app’s process types to standard-1x and preserves the current number of dynos:

$ heroku ps:type standard-1x

View Your Processes’ Dyno Types

To view the current dyno type for each process type, use the ps command:

$ heroku ps
=== web (standard-2x): `bundle exec puma -C config/puma.rb`
web.1: up 2015/03/27 14:27:58 (~ 6h ago)
web.2: up 2015/03/27 14:47:04 (~ 6h ago)
web.3: up 2015/03/27 15:08:23 (~ 5h ago)

=== worker (standard-1x): `bundle exec rake worker:job`
worker.1: up 2015/03/27 14:39:04 (~ 6h ago)
worker.2: up 2015/03/27 15:08:24 (~ 5h ago)
worker.3: up 2015/03/27 14:30:55 (~ 6h ago)

Setting One-Off Dyno Types

You can set the dyno type for memory-intensive one-off dynos. To learn more, see One-Off Dynos.

Scheduler

The Scheduler add-on uses one-off dynos, and as such it supports all one-off dyno types that your app can provision.