How to check if a website uses Next.js

By SearchWebCode · Updated November 7, 2026 · Detection · 2 min read

Search the page source for /_next/static. Then check for __NEXT_DATA__ or self.__next_f.push to identify the router's page data.

Next.js leaves recognizable asset paths and page-data scripts in many rendered pages. Use several markers together: a reference to one Next.js file can be copied into an article or embedded from another site.

Check the main source markers

Marker	What it indicates
`/_next/static/`	Next.js build assets. Check whether the script or stylesheet belongs to the page itself.
`__NEXT_DATA__`	A JSON data script associated with the Pages Router.
`self.__next_f.push`	Inline data used by App Router pages. This is an implementation marker, not a public version number.
`x-powered-by: Next.js`	An optional response header. Its absence does not rule out the framework.

Next.js documents Pages Router data in __NEXT_DATA__. App Router pages use a different data path, so a detector that checks only that element will miss them.

Inspect assets when the obvious path is missing

Open DevTools → Network and inspect the page's script and stylesheet requests. Next.js can serve static assets from a CDN using assetPrefix. A base path can also put another segment before /_next/.

The retained linktr.ee sample references /_marketing/_next/static/; www.theverge.com references /_next/static/media/. These illustrate stored asset paths, not a new live check of either site.

Search for Next.js websites

Build assets: "/_next/static".
Pages Router data: __NEXT_DATA__.
App Router data: self.__next_f.push.
Another visible integration: "/_next/static" "js.stripe.com/v3" requires both references in the homepage.

The Next.js asset sample reports 2,052,945 estimated matches. Inspect the surrounding tags before adding a result to a framework list. For variable asset strings, use the regex search examples.

Check hosting separately

Next.js can run on Vercel or other infrastructure. Framework assets do not identify the host, and a Cloudflare response can sit in front of a Next.js application. Use the Cloudflare header checks for that layer and compare other framework markers when the source is ambiguous.

For the general search method and its homepage-only coverage, see searching website source code.

Source counts checked 2026-10-14. They describe stored homepages, not live installations. How the counts are measured.

← All guides · Browse technologies · Search and export pricing

Frequently asked questions

Does every Next.js page contain __NEXT_DATA__?

No. It is a Pages Router marker. App Router pages use a different data path, so check the assets and other page-data scripts too.

Can a build ID tell me the Next.js version?

No. A build ID identifies a deployment build, not the framework's package version. Do not use it as a version or vulnerability test.

Does a Next.js asset path prove the site is on Vercel?

No. Next.js can be hosted elsewhere, and Vercel can serve applications built with other frameworks.