ExpressJS Cookies Management

npm install cookie-parser

const express = require('express');
const cookieParser = require('cookie-parser');
const app = express();

// Use cookie-parser middleware
app.use(cookieParser());

// Now you can access cookies via req.cookies

app.get('/set-cookie', (req, res) => {
  // Basic cookie
  res.cookie('username', 'John');

  // Cookie with options
  res.cookie('theme', 'dark', {
    maxAge: 24 * 60 * 60 * 1000, // 1 day in milliseconds
    httpOnly: true, // Can't be accessed by JavaScript
    secure: false, // Set to true for HTTPS only
    sameSite: 'lax' // CSRF protection
  });

  res.send('Cookies set!');
});

• maxAge How long the cookie lives (in milliseconds)
• expires Specific expiration date
• httpOnly Prevents JavaScript access (security against XSS)
• secure Only send over HTTPS
• sameSite CSRF protection (strict, lax, none)
• domain Which domain the cookie belongs to
• path Which paths the cookie is sent to

app.get('/get-cookie', (req, res) => {
  // Read all cookies
  console.log(req.cookies);

  // Read a specific cookie
  const username = req.cookies.username;
  const theme = req.cookies.theme;

  if (username) {
    res.send(`Welcome back, ${username}! Your theme is ${theme}`);
  } else {
    res.send('No cookies found');
  }
});

app.get('/clear-cookie', (req, res) => {
  // Clear a specific cookie
  res.clearCookie('username');
  res.clearCookie('theme');

  res.send('Cookies cleared');
});

const express = require('express');
const cookieParser = require('cookie-parser');
const app = express();

app.use(cookieParser());
app.use(express.urlencoded({ extended: true }));

// Login page
app.get('/login', (req, res) => {
  // Check if already logged in via cookie
  if (req.cookies.loggedIn === 'true') {
    return res.redirect('/dashboard');
  }

  res.send(`
    

      
      
      
         Remember me
      
      Login
    

  `);
});

// Handle login
app.post('/login', (req, res) => {
  const { username, password, remember } = req.body;

  // In a real app, you'd validate credentials against database
  if (username === 'john' && password === 'secret') {
    // Set cookie if remember me is checked
    if (remember) {
      res.cookie('loggedIn', 'true', {
        maxAge: 7 * 24 * 60 * 60 * 1000, // 7 days
        httpOnly: true
      });
      res.cookie('username', username, {
        maxAge: 7 * 24 * 60 * 60 * 1000
      });
    }
    res.redirect('/dashboard');
  } else {
    res.send('Invalid credentials');
  }
});

// Dashboard (protected)
app.get('/dashboard', (req, res) => {
  if (req.cookies.loggedIn === 'true') {
    res.send(`Welcome to your dashboard, ${req.cookies.username}! Logout`);
  } else {
    res.redirect('/login');
  }
});

// Logout
app.get('/logout', (req, res) => {
  res.clearCookie('loggedIn');
  res.clearCookie('username');
  res.send('Logged out! Login again');
});

• Cookies store small amounts of data on the client browser.
• Use cookie-parser middleware to handle cookies in Express.
• Set cookies with res.cookie(name, value, options).
• Read cookies from req.cookies.
• Delete cookies with res.clearCookie(name).
• Important options: maxAge, httpOnly, secure, sameSite.
• Cookies are commonly used for authentication, preferences, and tracking.