How to Build Modern SaaS Applications with Next.js
2/20/2026
4 min read
# How to Build Modern SaaS Applications with Next.js
Next.js is a powerful React framework that makes building modern web applications simpler and more efficient. In this article, we will guide you through a complete step-by-step process on how to use Next.js to build a simple SaaS application. We will cover the entire process from setting up the development environment to creating basic functionalities.
## 1. Environment Preparation
Before we begin, we need to ensure that your development environment is ready. Please follow the steps below:
### 1.1 Install Node.js and npm
Make sure that Node.js and npm are installed on your computer. You can run the following commands in the terminal to check the versions:
```bash
node -v
npm -v
```
If you have not installed them yet, you can go to [Node.js official website](https://nodejs.org/) to download and install.
### 1.2 Create a Next.js Project
Run the following command in the terminal to create a new Next.js project:
```bash
npx create-next-app@latest my-saas-app
cd my-saas-app
```
This will create a new project named `my-saas-app` and automatically install the required dependencies.
## 2. Project Structure
In the `my-saas-app` directory, you will see the following basic structure:
```
my-saas-app/
├── pages/
│ ├── api/
│ ├── _app.js
│ ├── index.js
│ └── ...
├── public/
├── styles/
└── ...
```
- **pages/**: Contains the pages of the application.
- **public/**: Contains public resources such as images, icons, etc.
- **styles/**: Contains CSS files.
## 3. Build Core Features
In this section, we will implement a simple user registration and login system.
### 3.1 Set Up Database
In this example, we will use Supabase as the backend service. Please follow the steps below:
1. Go to [Supabase official website](https://supabase.io/) and create an account.
2. Create a new project and note down your database URL and API key.
3. Connect to the database and create the following user table:
```sql
create table users (
id serial primary key,
email text unique not null,
password text not null
);
```
### 3.2 Install Supabase Client
Install the Supabase client library in your Next.js project:
```bash
npm install @supabase/supabase-js
```
### 3.3 Create User Registration Page
In the `pages/` directory, create a new file `register.js` and add the following content:
```jsx
import { useState } from 'react';
import { createClient } from '@supabase/supabase-js';
const supabase = createClient('YOUR_SUPABASE_URL', 'YOUR_SUPABASE_ANON_KEY');
const Register = () => {
const [email, setEmail] = useState('');
const [password, setPassword] = useState('');
const handleRegister = async () => {
const { user, error } = await supabase.auth.signUp({
email,
password,
});
if (error) {
console.error(error);
} else {
alert('Registration successful!');
}
};
return (
);
};
export default Register;
```
### 3.4 Create User Login Page
Similarly, in the `pages/` directory, create a new file `login.js` and add the following content:
```jsx
import { useState } from 'react';
import { createClient } from '@supabase/supabase-js';
const supabase = createClient('YOUR_SUPABASE_URL', 'YOUR_SUPABASE_ANON_KEY');
const Login = () => {
const [email, setEmail] = useState('');
const [password, setPassword] = useState('');
const handleLogin = async () => {
const { user, error } = await supabase.auth.signIn({
email,
password,
});
if (error) {
console.error(error);
} else {
alert('Login successful!');
}
};
return (
);
};
export default Login;
```
## 4. Deploy the Application
### 4.1 Choose a Deployment Platform
We will use Vercel to deploy our Next.js application. Please follow the steps below:
1. Go to [Vercel official website](https://vercel.com/) and register an account.
2. Create a new project and select your GitHub repository.
3. Make sure to add the Supabase URL and API key in the environment variables.
4. Click deploy and wait for Vercel to complete the deployment.
### 4.2 Verify Deployment
After deployment is complete, you will receive a public URL. Visit this URL to ensure the application is running properly.
## 5. Summary
Through the steps in this article, you have successfully built a simple SaaS application using Next.js, including user registration and login functionalities. The power of Next.js lies in its flexibility and efficiency, allowing for easy scaling to meet more complex needs. We hope you can continue to delve deeper on this foundation and build more amazing applications!
Register
setEmail(e.target.value)} /> setPassword(e.target.value)} />Login
setEmail(e.target.value)} /> setPassword(e.target.value)} />Published in Technology
