🚀 Deploy Next.js Serverless Functions on AWS Using OpenNext

Vercel’s deployment platform is fantastic — but what if you want to host your Next.js app on AWS, with full control over infrastructure, cost, and scaling?

That’s where OpenNext comes in — an open-source toolkit that takes your Next.js app and builds it into a serverless-friendly format that can run anywhere, including AWS Lambda, Cloudflare Workers, and Netlify.

In this guide, we’ll go hands-on to deploy a Next.js app using OpenNext on AWS Lambda, step by step.

🧠 What is OpenNext?

OpenNext is an open-source project that replicates how Vercel runs Next.js in serverless environments.

It:

Converts your .next build output into AWS Lambda–compatible functions
Packages static assets for S3 + CloudFront
Handles ISR (Incremental Static Regeneration)
Generates an open-next.config.mjs for fine control

👉 Think of it as Vercel’s build pipeline, open-sourced.

🗂 Step 1: Setup Your Next.js App

Create a new Next.js app (if you don’t already have one):

npx create-next-app@latest my-serverless-app
cd my-serverless-app

Let’s add a simple API route that we’ll deploy as a serverless function:

// app/api/hello/route.ts
export async function GET() {
  return Response.json({ message: "Hello from Serverless Lambda 👋" });
}

Test it locally:

npm run dev

Visit http://localhost:3000/api/hello — you should see your JSON response.

🧩 Step 2: Install and Configure OpenNext

Install OpenNext as a dev dependency:

npm install -D open-next

Then create a config file:

touch open-next.config.mjs

Add this content:

export default {
  default: {
    mode: "serverless",
  },
};

Now build using OpenNext:

npx open-next build

This will generate a .open-next/ folder with:

Lambda-ready function bundles (server-function/)
Static files for S3
Configuration metadata

☁️ Step 3: Deploy to AWS Lambda (Using AWS SAM)

Install the AWS SAM CLI (Serverless Application Model):

brew install aws-sam-cli

Then initialize your deployment setup:

sam init --name nextjs-open-next --runtime nodejs20.x --app-template hello-world

Replace the SAM project’s template.yaml with:

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: Deploy Next.js app built with OpenNext

Resources:
  NextServerFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: NextServer
      Handler: index.handler
      Runtime: nodejs20.x
      CodeUri: .open-next/server-function
      MemorySize: 512
      Timeout: 10
      Events:
        Api:
          Type: Api
          Properties:
            Path: /{proxy+}
            Method: ANY

🚀 Step 4: Deploy the Stack

Run:

sam build
sam deploy --guided

You’ll be asked for:

Stack name (e.g. next-open-next)
AWS region
Confirmation prompts

After deployment, AWS SAM will output an API Gateway URL.
Visit that URL → your app and API routes are now live! 🎉

🧠 Step 5: How It Works Internally

OpenNext:

Converts each Next.js route and API into separate AWS Lambda functions.
Sends static assets to S3.
Uses CloudFront for caching and ISR invalidation.
Handles /_next/data/ and /_next/image paths like Vercel.

So you get the same performance and behavior as Vercel — just fully on AWS.

🛠 Troubleshooting Tips

Cold Starts: Use AWS Lambda Provisioned Concurrency if latency matters.
ISR Pages Not Updating? Check your CloudFront invalidation setup.
Memory Errors: Increase Lambda memory (512MB–1GB is typical).

✅ Step 6: Automate Future Deployments

You can use GitHub Actions to automate builds and deployments:

# .github/workflows/deploy.yml
name: Deploy Next.js to AWS Lambda
on:
  push:
    branches: [ main ]

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - run: npm ci
      - run: npx open-next build
      - run: sam deploy --no-confirm-changeset --stack-name next-open-next --region us-east-1

🎯 Final Thoughts

Using OpenNext gives you:

Full control of your infra (AWS instead of Vercel)
Lower cost scaling for high-traffic sites
Better transparency for debugging and tuning

It’s perfect if you want to keep Next.js’s developer experience but host in your own cloud.

🔗 Resources

💡 Pro Tip:
You can also use SST (Serverless Stack) — it integrates with OpenNext and automates your AWS deployment even more smoothly.

✨ Now your Next.js app runs fully on AWS Lambda — serverless, scalable, and open-source powered.