Free scan / Next.js

Is your Next.js app production-ready?

Paste your URL. Get a free automated check in under 60 seconds. Catches secrets in the bundle, missing auth guards, broken routes, and slow cold starts before your users find them.

Definition

A Next.js app is production-ready when secrets never reach the client bundle, auth is enforced at the API and middleware level (not just in the UI), payment flows handle errors and webhook replays correctly, all routes return the expected status codes, and the bundle is small enough to load in under 2.5 seconds on a real connection. Apps built with AI coding tools often pass visual testing but fail on two or three of these silently, usually secrets exposure and missing server-side auth guards.

Secrets in the client bundle
NEXT_PUBLIC_ prefix mistakes and direct imports in client components expose API keys to every browser.
Auth guards at the route level
A login page does not mean protected routes are actually protected. Middleware and API handlers need independent auth checks.
Payment and webhook paths
Stripe webhooks without signature verification accept replay attacks. Error states that return 200 break retry logic.
Bundle size and cold starts
Vercel cold starts on underpowered routes and large bundles tank Core Web Vitals on first load, which hurts conversion before you notice.

Run the free scan

Enter your deployed Next.js URL. The scan checks your live app, not source code, so deploy to Vercel or your host first.

What automated checks miss

The scan covers the surface. These issues require a human looking at your running app.

Row-level security policy gaps
A Supabase RLS policy that looks correct in the editor can still allow cross-tenant reads when hit from the right angle in production. A static scan cannot reproduce this.
Auth edge cases under real sessions
Token expiry handling, session refresh races, and JWT claims that do not match what your API routes actually check. These only surface under real session state.
Cross-tenant data access
Can user A read or modify user B's data by manipulating a query parameter or API payload? This requires live behavioral testing against your running app.
Webhook replay and idempotency
Does your Stripe integration handle duplicate webhook delivery? Does your order fulfillment run twice if the webhook fires twice? Only a targeted probe can confirm.

The pre-launch validation covers all of the above with live behavioral replay against your running app. Every finding ships with a re-runnable proof and a fix formatted for your AI tool.

See what a pre-launch validation covers →
FAQ

Common questions about Next.js production readiness

A Next.js app is production-ready when it correctly separates server and client code so secrets never reach the browser, routes are protected by real auth guards not just UI-level checks, payment and webhook paths handle errors and replay attacks, and the bundle is small enough to load fast on a real connection. Apps built with AI tools often pass manual testing but fail on two or three of these silently.
The scan checks whether secrets are leaking into the client bundle, whether auth is enforced at the route or API level, whether payment flows return correct status codes under failure, whether key links return 200, and whether Core Web Vitals are in acceptable range. It runs against your live URL, not against source code.
Yes, and especially so. AI coding tools generate correct-looking Next.js that routes secrets through environment variables, then accidentally exposes them by using them in a client component or an API route that lacks the server-only guard. The scan specifically looks for this pattern.
Passing the automated scan means the surface checks are clear. It does not cover row-level security policies, cross-tenant data isolation, auth edge cases, or Stripe webhook replay handling. Those require a human looking at your actual Supabase config and running live behavioral tests. A pre-launch validation covers all of that.
A local build tells you whether TypeScript compiles and whether Next.js can render the pages. It does not tell you whether secrets are reachable from the browser in the deployed environment, whether your auth middleware actually fires on protected routes in production, or whether your Vercel config has CORS or header mismatches. This scan checks the deployed URL.
Each finding includes a summary of what was detected and what it means for your launch. For quick fixes you can usually resolve them in your AI tool with a targeted prompt. For deeper issues, like an auth guard that is missing at the API level or a Stripe webhook without signature verification, a pre-launch validation will reproduce the exact failure and give you a fix formatted for your AI tool.

Last updated: 2026-06-20