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How to add login, signup, and user management to your web app. Protect data, personalize experiences, and control access — your Backend handles this with API routes and Middleware. You'll also want a database to store user information.
Don't worry — you won't write any authentication code by hand. Your AI tool handles all the technical parts. This guide helps you understand the concepts so you can describe what you want.
Keep personal information, passwords, and payment details safe from unauthorized access.
Show each user their own dashboard, settings, saved items, and preferences.
Restrict pages and features to logged-in users, admins, or specific roles.
Drop-in authentication components with a beautiful UI. Handles sign-in, sign-up, user profiles, and multi-factor auth out of the box.
Pros
Easiest setup — add components and it works
Beautiful pre-built UI (SignIn, SignUp, UserButton)
Generous free tier (10,000 monthly active users)
Cons
Paid plans can get expensive at scale
Less control over the auth UI
Open-source authentication library for Next.js. Supports dozens of login services (Google, GitHub, etc.) with full control over the flow.
Pros
Completely free and open source
Supports 50+ login services (Google, GitHub, etc.)
Full control over database and session handling
Cons
More setup and configuration required
Needs more setup — your AI tool can help
Authentication built into the Supabase platform. Email/password, magic links, and social logins with controls for who can see what data.
Pros
Integrated with Supabase database and storage
Controls who can see what data for fine-grained access
Magic link (passwordless) login built in
Cons
Tied to the Supabase ecosystem
UI components are more basic
Google's authentication service. Supports email, phone, Google, Facebook, Apple, and more. Great ready-made tools for web and mobile.
Pros
Excellent mobile support (iOS, Android, Flutter)
Phone number authentication built in
Backed by Google infrastructure
Cons
Tied to the Firebase/Google ecosystem
Can be complex to set up with Next.js
Visual mockups of the most common authentication UI patterns you'll build.
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Standard OAuth button patterns — learn more in our social login guide
Logged-in user menu pattern
Jane Doe
jane@example.com
A session stores your login info on the server — like a hotel keycard that the front desk keeps track of. A JWT stores it in a token your browser holds — like a stamped hand at a concert. Both prove you're logged in, just in different ways.
Let users sign in with their Google or GitHub account instead of creating a new password. Your app never sees their password — Google or GitHub confirms who they are and sends the info back to your app.
Some pages should only be visible to logged-in users. If someone who isn't signed in tries to visit those pages, they get sent to the login page instead. Common examples: dashboard, settings, profile, billing.
Not all logged-in users should see everything. Roles (admin, editor, viewer) control what each user can do. Permissions are the specific actions a role allows (create, read, update, delete).
The fastest way to add login to your app. No coding knowledge needed — just follow these steps and let your AI tool do the heavy lifting.
Go to clerk.com and sign up for a free account. Create a new application and pick which login methods you want (Google, GitHub, email, etc.).
In the Clerk dashboard, find your API keys (they look like long strings of letters and numbers). You'll need two: a "Publishable Key" and a "Secret Key". Keep these private — they connect your app to Clerk.
Tell your AI tool:
"Add Clerk authentication to my Next.js app. Use these API keys: [paste your keys]. Set up Google and GitHub login. Add a sign-in page at /sign-in and a sign-up page at /sign-up."
Tell your AI tool:
"Make the /dashboard and /settings pages require login. If someone isn't signed in, send them to the /sign-in page."
Tell your AI tool:
"Add a user button to the top-right corner of my navbar. When someone is logged in, show their avatar. When they click it, show a dropdown with profile, settings, and sign-out options. Use Clerk's UserButton component."
Email/password form with social login buttons (Google, GitHub). Include 'Forgot password' link and 'Sign up' redirect.
Name, email, password fields with validation. Password strength indicator. Terms of service checkbox. Email verification.
Redirect unauthenticated users to login. Show user-specific data, settings, and navigation only when logged in.
Avatar/initials button in the navbar that opens a dropdown with profile, settings, and sign out options.
Show or hide UI elements based on user role. Admins see an admin panel. Editors can edit content. Viewers can only read.
Copy-paste these into your AI tool (Claude Code, Cursor, Bolt, etc.) to add login features to your app.
"Add Google and GitHub login to my app using Clerk. Create a sign-in page and a sign-up page with social login buttons."
"Make my dashboard and settings pages require login. If someone isn't signed in, send them to the sign-in page."
"Add a user avatar button to the top-right corner of my navbar. When clicked, show a dropdown with profile, settings, and sign-out options."
"Set up role-based access so admin users can see an admin page, but regular users get redirected away from it."
"Add email and password login to my app using NextAuth.js. Include a custom sign-in page with email and password fields."
Copy-paste these prompts into your AI tool to apply what you just learned.
ADD AUTH WITH CLERK
"Add user authentication to my Next.js app using Clerk. Include sign-up, sign-in, and a protected dashboard page. Add Google and GitHub as social login options."
PROTECT PAGES
"Protect my [dashboard/settings/admin] pages so only logged-in users can access them. Redirect unauthenticated users to the login page."
ADD ROLE-BASED ACCESS
"Add user roles to my app (admin, editor, viewer). Admin users can access the /admin page. Editors can create and edit content. Viewers can only read. Show different navigation items based on role."
