Changing a Next.js SSG App to SSR on Amplify Hosting

If you want to change to the application type from SSR to SSG, or SSG to SSR, then the platform and framework type needs to be changed in your application settings in Amplify Hosting. If not, you’ll likely hit deploy errors or 503s when the site builds and deploys.

The current framework type is listed in the App settings -> Building settings -> App build specification. This is determined when the application is created. For Next.js SSR apps, the type is selected if the build command in package.json is next build. The match criteria for each app build type is explained in the Deploying a Next.js SSR app with Amplify documentation.

Change an SSG app to SSR #

Use the AWS CLI to modify the framework value for the application.

App Type #

First update the app to have a --platform type of WEB_DYNAMIC.

Then, change the --framework to Next.js - SSR if the app is not using an Amplify Backend.

aws amplify update-app --app-id <APP_ID> --platform WEB_DYNAMIC --region <REGION>

aws amplify update-branch --app-id <APP_ID> --branch-name <BRANCH_NAME> --framework 'Next.js - SSR' --region <REGION>

SSR with Amplify Backend #

Change the --framework to Next.js - SSR - Amplify if the application is using an Amplify Backend.

App Build settings #

Next, adjust the application build settings to reflect an SSR application. As noted above, Amplify sets the app type when the app is first created, so this will need updated for SSR.

As an example, it should resemble:

version: 1
frontend:
  phases:
    preBuild:
      commands:
        - yarn install
    build:
      commands:
        - yarn run build
  artifacts:
    baseDirectory: .next
    files:
      - '**/*'
  cache:
    paths:
      - node_modules/**/*

Change an SSR app to SSG #

If you need to change the app to SSG, then follow the steps outlined in the Amplify Hosting FAQ - Convert an SSR App to SSG.

Rewrites #

The rewrite will be added after the SSR app is built/deployed. You should already have one of the rewrite lines in that config if one of your branches is SSR and successfully deploying.