Best A/B Testing Tool for Next.js (2025)

Next.js is the framework of choice for modern web apps. But A/B testing in Next.js can be tricky — SSR, hydration, and React's rendering model create unique challenges. ExperimentHQ solves them all, making it the #1 A/B testing tool for Next.js.

The A/B Testing Challenge in Next.js

Traditional A/B testing tools weren't built for React frameworks. They cause problems:

⚠️ Flicker Issues

Users see the original before the variant loads

⚠️ Hydration Mismatches

Server and client render different content

⚠️ SEO Impact

Client-side changes can hurt search rankings

⚠️ Complex Setup

Most tools require SDK integration and config

ExperimentHQ solves all of these. Our script loads early and applies changes before React hydrates, eliminating flicker and hydration issues.

Why ExperimentHQ is Perfect for Next.js

Zero Flicker

Tests apply before hydration. No flash of original content.

SSR Compatible

Works seamlessly with Server Components, SSR, SSG, and ISR.

Real-Time Analytics

Watch conversions update live. Statistical significance calculated automatically.

App Router Ready

Full support for Next.js 13+ App Router and Pages Router.

Install in 5 Minutes

App Router (Next.js 13+)

app/layout.tsx

import Script from 'next/script'

export default function RootLayout({ children }) {
  return (
    <html>
      <head>
        <Script 
          src="https://cdn.experimenthq.io/snippet.min.js" 
          data-site="YOUR_PUBLIC_KEY"
          strategy="afterInteractive"
        />
      </head>
      <body>{children}</body>
    </html>
  )
}

Pages Router

pages/_app.tsx

import Script from 'next/script'

export default function App({ Component, pageProps }) {
  return (
    <>
      <Script 
        src="https://cdn.experimenthq.io/snippet.min.js" 
        data-site="YOUR_PUBLIC_KEY"
        strategy="afterInteractive"
      />
      <Component {...pageProps} />
    </>
  )
}

That's it! No SDK to install, no environment variables to configure. Just add the Script component.

Works With Your Entire Stack

ExperimentHQ integrates seamlessly with the Next.js ecosystem:

Vercel

Netlify

AWS Amplify

Tailwind CSS

shadcn/ui

Prisma

NextAuth

tRPC

+ Any other

6 High-Impact Tests for Next.js Apps

1 Landing page hero section

Very High ImpactEasy

2 Pricing page layout

Very High ImpactMedium

3 Sign-up flow steps

High ImpactMedium

4 Feature page copy

High ImpactEasy

5 Navigation structure

Medium ImpactEasy

6 CTA button variations