Last updated October 22, 2025

This article describes how to upgrade the major Postgres version of a Heroku Postgres database. The most recent major Postgres version supported by Heroku is 17.

You can only upgrade your major Postgres version via the Heroku CLI. It’s a significant operation that you must do with care.

Heroku supports three methods for upgrading the Postgres version of your database. All methods require some application downtime to ensure that no data is lost during the upgrade.

The upgrade methods in this article cover upgrading the database version of a Heroku Postgres database. Upgrading the version on a leader database through the Direct upgrade method automatically upgrades any follower databases. If you upgrade with the Follower Failover or Data Copy upgrade methods, you must create new follower databases after your new leader database is upgraded.

Upgrading with the Direct Upgrade Method

You can use the Direct upgrade method to perform version upgrades on Essential-tier databases and Standard-tier and higher leader databases. The Direct upgrade method differs depending on your database plan. Upgrades on Essential databases run immediately, while Standard-tier and higher databases follow a maintenance-like process.

This method upgrades the version of your database directly, maintaining your existing database add-on. Direct upgrades automatically control and restrict login access to the database while the upgrade is running to prevent lost writes. Access is restored after the upgrade completes.

Essential-Tier

Direct upgrades on Essential-tier databases immediately upgrade your database version. This process transfers the data to a new database on the target Postgres version that replaces your existing database. Database access is restricted during the upgrade, and automatically restored after the upgrade completes. This upgrade method requires app downtime of around 10 minutes for most use cases, although this amount can vary depending on the data size of your database.

To upgrade the version on an Essential-tier database, run pg:upgrade:run directly on your database:

$ heroku pg:upgrade:run HEROKU_POSTGRESQL_RED --app example-app

By default, pg:upgrade:run updates your database to the latest supported version. You can specify a target version with the --version flag.

To monitor the upgrade progress, run pg:upgrade:wait:

$ heroku pg:upgrade:wait Heroku_POSTGRESQL_RED --app example-app
Waiting for database postgresql-crystalline-69217... Available

You receive separate email notifications when the version upgrade starts and after it’s complete.

Standard-Tier and Higher

Direct upgrades on Standard-tier and higher databases automate the Postgres major version upgrade of an existing database. You can schedule and run the upgrade similar to a Heroku Postgres database maintenance.

The upgrade commands use the PostgreSQL pg_upgrade utility to upgrade your Postgres version in-place. This upgrade method requires app downtime of around 10 minutes for most use cases. Database access is restricted when the upgrade starts, and automatically restored after the upgrade completes.

If your database has any followers, the followers are also automatically upgraded to the target version after your leader database is upgraded. Existing database followers remain operational during their parent database upgrade. After the leader database is upgraded, followers experience replication lag until they’re automatically replaced and upgraded to the target version. The followers can continue replicating from the upgraded leader.

To upgrade the major version on a Standard-tier and higher database:

1. Run pg:upgrade:prepare to prepare your leader database for upgrade and schedule it during the next available maintenance window.
2. Wait until the scheduled maintenance for the upgrade to start automatically, or run pg:upgrade:run to start the prepared upgrade at any time.

You can test the version upgrade beforehand with the pg:upgrade:dryrun command to verify your database’s schema and data are compatible with the new Postgres version. To test your app’s compatibility and performance with the new Postgres version, follow the Testing with a Forked Database instructions.

You can keep a copy of your database in the old version by forking the database or creating a follower database and unfollowing it before starting the upgrade with pg:upgrade:run.

1. Prepare Your Version Upgrade

To begin, run pg:upgrade:prepare on your leader database:

$ heroku pg:upgrade:prepare HEROKU_POSTGRESQL_RED --app example-app
Preparing upgrade on postgresql-crystalline-69217... done
Your database is scheduled for upgrade during your next available maintenance window.
Run heroku pg:upgrade:wait to track its status.
You can also run this upgrade manually before the maintenance window with heroku pg:upgrade:run. Note: You can only run the upgrade after it's fully prepared, which can take up to a day.

This command prepares the upgrade and schedules it for the next available maintenance window. Preparing the upgrade can take up to a day. You receive an email notification after the upgrade is prepared and scheduled. You can check the status of the upgrade preparation with pg:upgrade:wait or pg:info. For example, with pg:upgrade:wait:

$ heroku pg:upgrade:wait HEROKU_POSTGRESQL_RED --app example-app
Waiting for database postgresql-crystalline-69217... ⣟ preparing service for upgrade

You can cancel your prepared upgrade before the scheduled maintenance begins or before you start the upgrade with pg:upgrade:cancel.

2. Run Your Version Upgrade

After your upgrade is prepared and scheduled, you can either wait until the maintenance window for the upgrade to start automatically, or start the version upgrade manually on your leader database with the command pg:upgrade:run:

$ heroku pg:upgrade:run HEROKU_POSTGRESQL_RED --app example-app

After starting the upgrade, you can’t cancel it. The upgrade process restricts database access after the upgrade starts to prevent writes, and restores access after it completes. You receive an email notification after your database upgrade completes.

You can check the status of the running upgrade with pg:upgrade:wait:

$ heroku pg:upgrade:wait HEROKU_POSTGRESQL_RED --app example-app
Waiting for database postgresql-crystalline-69217... ⣟ (1/8) checking upgrade service

As part of the pg:upgrade:run process, Heroku Postgres runs ANALYZE on your database. This process recalculates statistics for your database to make sure the Postgres query planner has up-to-date information even after a version upgrade.

The pg:upgrade:run command can fail due to errors such as incompatible data types in a table in your database. If your upgrade fails, running pg:upgrade:wait or pg:wait returns version upgrade error, check your Heroku email notifications for details. In the case of errors during a Direct upgrade, the upgrade automatically cancels and restores access back to your database on the old version. You receive an email notification with the error details. You can prepare a new upgrade and try upgrading again after resolving the error.

After the database upgrade is completed, this method automatically replaces any followers on your database and upgrades them to the target version. It takes some time to replace and upgrade all followers. The existing followers pending upgrade remain operational but experience replication lag until they’re replaced. You can verify the status and version of every follower with heroku pg:info.

$ heroku pg:upgrade:wait HEROKU_POSTGRESQL_RED --app example-app
Waiting for database postgresql-crystalline-69217... ⣟ (8/8) recreating followers in the new postgres version. Use `heroku pg:wait` to track its status.

$ heroku pg:info HEROKU_POSTGRESQL_PURPLE -a example-app
=== HEROKU_POSTGRESQL_PURPLE_URL

Plan:                  Standard 0
Status:                Recreating follower to follow the new leader
PG Version:            16.9
...
Following:             HEROKU_POSTGRESQL_RED

Upgrading with the Follower Failover Method

Performing a version upgrade with the Follower Failover method involves upgrading a follower of your database and promoting it as your new, upgraded database. With this method, you perform the upgrade on a separate add-on and your old database remains available after the upgrade. During the upgrade process, you must put your app in maintenance mode and prevent any writes to your original database. The Follower Failover method requires app downtime on the order of 20-30 minutes, considering the upgrade time itself and the manual steps required.

If you must upgrade both the Postgres version and your plan, provision a new follower on a different plan and use pg:upgrade:run as part of the changeover process.

You can test the version upgrade using this method beforehand with a forked database.

1. Provision a Follower Database

To begin, create a follower for your database and wait for the follower to catch up to the leader database. You can provision the plan best suited for your needs.

The example creates a follower with a standard-2 plan for the HEROKU_POSTGRESQL_LAVENDER database. Replace HEROKU_POSTGRESQL_LAVENDER with the config var, attachment or add-on name of the leader database you’re upgrading.

$ heroku addons:create heroku-postgresql:standard-2 --app example-app -- --follow HEROKU_POSTGRESQL_LAVENDER
Adding heroku-postgresql:standard-2 to example-app... done, v71 ($200/mo)
Attached as HEROKU_POSTGRESQL_WHITE
Follower will become available for read-only queries when up-to-date
Use `heroku pg:wait` to track status

The follower is considered “caught up” when it is within 200 commits of the primary database. You can check how many commits the follower is behind with the pg:info command. See the Behind By row of the follower database:

$ heroku pg:info --app example-app
=== HEROKU_POSTGRESQL_LAVENDER
Plan:        Standard 0
Status:      available
...
=== HEROKU_POSTGRESQL_WHITE
Plan:        Standard 2
Status:      available
...
Following:   HEROKU_POSTGRESQL_LAVENDER (DATABASE_URL)
Behind By:   125 commits

2. Enter Maintenance Mode to Prevent Database Writes

It’s important that no new data is written to your current primary database during the upgrade process, because it doesn’t transfer to the new database when the follower starts upgrading. To accomplish this, place your app into maintenance mode. If you have scheduler jobs running as well, or other external systems connecting to the database, disable them. Databases continue to accrue billing hours while in maintenance mode.

$ heroku maintenance:on --app example-app
Enabling maintenance mode for example-app... done

3. Upgrade the Follower Database

Now that you are in maintenance mode and no additional data is being written to the primary database, you can upgrade the follower database.

Wait for the follower database to fully catch up to the primary as indicated by being behind by 0 commits.

$ heroku pg:info --app example-app
=== HEROKU_POSTGRESQL_LAVENDER_URL
Plan:        Standard 0
Status:      available
...
=== HEROKU_POSTGRESQL_WHITE_URL
Plan:        Standard 2
Status:      available
...
Following:   HEROKU_POSTGRESQL_LAVENDER_URL (DATABASE_URL)
Behind By:   0 commits

If you don’t wait for the follower to catch up, then you get an error message when you start the upgrade:

 ▸    database is too far behind its leader. Wait until your follower catches up with its leader and try again.

When the follower is caught up, use the pg:upgrade:run command to upgrade the Postgres version of the follower in place. Upgrading also causes the follower to unfollow the primary database. This step usually requires about 20 minutes to complete.

$ heroku pg:upgrade:run HEROKU_POSTGRESQL_WHITE --app example-app

You can monitor the progress of the upgrade with pg:upgrade:wait or pg:wait:

$ heroku pg:upgrade:wait HEROKU_POSTGRESQL_WHITE --app example-app
Waiting for database HEROKU_POSTGRESQL_WHITE_URL... performing final cleanup steps after upgrade

As part of the pg:upgrade:run process, Heroku Postgres runs ANALYZE on your database. This process recalculates statistics for your database to make sure the Postgres query planner has up-to-date information even after a version upgrade. All credentials and custom credentials are also rotated as a part of the upgrade process.

The pg:upgrade:run command can fail due to errors such as incompatible data types in a table in your database. If your upgrade fails, you receive an email notification with the error details. Also, running pg:upgrade:wait or pg:wait returns version upgrade error, check your Heroku email notifications for details. In the case of any errors, deprovision the follower that failed to upgrade and retry the upgrade after resolving the error on your leader database.

4. Promote or Attach the New Database

If DATABASE_URL was the config var for your previous primary database, use pg:promote to promote the newly upgraded database as the new DATABASE_URL. pg:promote creates an alternate attachment for the old primary database, assigned with a new HEROKU_POSTGRESQL_<color>_URL config var. The promotion process triggers a release and restarts the app.

$ heroku pg:promote HEROKU_POSTGRESQL_WHITE --app example-app
Promoting HEROKU_POSTGRESQL_WHITE_URL to DATABASE_URL... done

Now the follower database you created in step 1 is the primary database (DATABASE_URL) for the app, although the app isn’t receiving new requests yet.

If the database you’re upgrading has a different config var other than the default DATABASE_URL, use heroku addons:attach to promote your newly upgraded database with the required alias or attachment name. If you attached your original primary database to multiple apps, you must attach your new upgraded database to those apps with addons:attach.

$ heroku addons:create heroku-postgresql:standard-0 -a example-app -- --follow DATABASE_URL

$ heroku pg:connection-pooling:attach DATABASE_URL --as MY_DATABASE_CONNECTION_POOL -a example-app

5. Exit Maintenance Mode

To resume normal application operation, scale any non-web dynos back to their original levels (for example, heroku ps:scale worker=1).

Finally, turn off maintenance mode:

$ heroku maintenance:off --app example-app

Your application is now receiving requests to your upgraded database instance. You can confirm this by running heroku pg:info. The database denoted by DATABASE_URL is considered the primary database.

Upgrading with the Data Copy Method

Performing a version upgrade with the Data Copy version upgrade method involves copying the data from your database to a new database that’s on the target version. When the data copy completes, you can promote the database on the target version and start using it as your new primary database. During the data copy process, you must put your app in maintenance mode to prevent any writes to your original database.

The Data Copy upgrade method uses native PostgreSQL backup and restore utilities to transfer your data to a newly provisioned database. This process helps reduce bloat, the extra space taken up by dead rows on your database, and can save disk space.

This method requires approximately 3 minutes of app downtime per GB of your current database, although this amount can vary substantially depending on your schema and database plan. You can estimate your required downtime by testing the upgrade and performing the upgrade process on a new database on a non-production application.

This method supports upgrades between all supported Heroku Postgres plans and versions. pg:copy only copies your default credential and the data it has access to. Any additional credentials and data that only they can access don’t get copied. You can also test the version upgrade using this method beforehand.

1. Provision a New Database

Provision a new Heroku Postgres database with your desired plan. In the example, the standard-0 plan is used, but you can provision the plan best suited for your needs:

$ heroku addons:create heroku-postgresql:standard-0 --app example-app
Creating heroku-postgresql:standard-0 on ⬢ example-app... ~$0.069/hour (max $50/month)
The database should be available in 3-5 minutes.

Use `heroku pg:wait` to track status.
postgresql-concave-52656 is being created in the background. The app will restart when complete...

Standard, Premium, and Private-tier databases take a few minutes to provision. You can use the pg:wait command to notify you when provisioning is complete:

$ heroku pg:wait -a example-app
Waiting for database postgresql-concave-52656... ⢿ preparing

2. Enter Maintenance Mode to Prevent Database Writes

It’s important that no new data is written to your current primary database during the upgrade process, because it doesn’t transfer to the new database. To accomplish this, place your app into maintenance mode. If you have scheduler jobs running as well, or other external systems connecting to the database, disable them.

$ heroku maintenance:on -a example-app
Enabling maintenance mode for example-app... done

3. Transfer Data to the New Database

To copy data from your current database to the newly provisioned database, use the pg:copy command to specify the source and target of the data transfer. Set your current database as the source and the new database you provisioned in Step 1 as the target. In this example, the DATABASE_URL is the source of the data in the transfer and HEROKU_POSTGRESQL_PINK is the target database.

$ heroku pg:copy DATABASE_URL HEROKU_POSTGRESQL_PINK --app example-app

!    WARNING: Destructive Action
!    Transfering data from DATABASE_URL to HEROKU_POSTGRESQL_PINK
!    This command will affect the app: example-app
!    To proceed, type "example-app" or re-run this command with --confirm example-app

example-app

You can also use the add-on name of your new database, for example, postgresql-concave-52656:

$ heroku pg:copy DATABASE_URL postgresql-concave-52656 --app example-app

4. Promote or Attach the New Database

If DATABASE_URL was the config var for your previous primary database, use pg:promote to promote the newly upgraded database as the new DATABASE_URL. pg:promote creates an alternate attachment for the old primary database, assigned with a new HEROKU_POSTGRESQL_<color>_URL config var. The promotion process triggers a release and restarts the app.

$ heroku pg:promote HEROKU_POSTGRESQL_PINK --app example-app
Promoting HEROKU_POSTGRESQL_PINK_URL to DATABASE_URL... done

Now the database you created in step 1 is the primary database (DATABASE_URL) for the app, although the app isn’t receiving new requests yet.

If the database you’re upgrading has a different config var other than the default DATABASE_URL, use heroku addons:attach to promote your newly upgraded database with the required alias or attachment name. If you attached your original primary database to multiple apps, you must attach your new upgraded database to those apps with addons:attach.

$ heroku addons:create heroku-postgresql:standard-0 -a example-app -- --follow DATABASE_URL

5. Exit Maintenance Mode

To resume normal application operation, scale any non-web dynos back to their original levels (for example, heroku ps:scale worker=1).

Finally, turn off maintenance mode:

$ heroku maintenance:off --app example-app

Your application is now receiving requests to your new database instance. You can confirm this by running heroku pg:info. The database denoted by DATABASE_URL is considered the primary database.

Deprovisioning the Old Primary Database

The Follower Failover and Data Copy upgrade methods involve creating a new database add-on, and your old database add-on isn’t automatically deprovisioned.

After you upgrade your database with the Follower Failover or Data Copy upgrade methods, be sure to deprovision your old primary database:

$ heroku addons:destroy HEROKU_POSTGRESQL_LAVENDER --app example-app