How to tell if a website is using nextjs ?

To determine if a website is using Next.js, you can follow these steps:

1. View the Source Code

Open the website in a browser, right-click on the page, and select 'View Page Source'. In the source code, search for keywords such as _next or Next.js. Next.js typically includes _next in the generated file paths, for example, in links to JavaScript or CSS files.

2. Check HTTP Response Headers

Use developer tools (F12) to inspect network requests and responses. In some cases, Next.js applications may include identifying information in their HTTP response headers, such as x-powered-by: Next.js.

3. Inspect Page Structure

Next.js typically uses <div id="__next"> to wrap page content. By examining the HTML structure of the page, you can find such clues.

4. JavaScript Runtime Detection

Execute some JavaScript code in the console to check for the presence of Next.js global variables or specific behaviors. For example, Next.js adds specific properties or methods to the window object.

5. Use Specialized Tools

Several browser extension tools, such as Wappalyzer or BuiltWith, can automatically detect the technology stack of a website, including whether Next.js is used.

Example

For example, if you visit a website such as example.com and see the following code snippet in the page source:

html
<link href="/next/static/css/styles.chunk.css?v=1" rel="stylesheet">

Or if you see the string _next in JavaScript file paths:

html
<script src="/next/static/chunks/main.js"></script>

This may indicate that the website is using Next.js. Additionally, if you see the response header containing:

shell
x-powered-by: Next.js

This is almost certainly a sign that the website uses Next.js. Furthermore, if you find:

html
<div id="__next">
  <!-- Page content -->
</div>

This is also a strong indicator of Next.js usage.

Note that because Next.js supports custom server configurations and static site exports, detection may not always be straightforward. In such cases, you may need to consider multiple factors to make a determination.