How to Clear Cookie in Express: Simple Guide

In Express, you clear a cookie by using res.clearCookie('cookieName'). This removes the cookie from the client by setting its expiration date to a past time.

Syntax

The basic syntax to clear a cookie in Express is:

• res.clearCookie(name, options)

Where:

• name is the name of the cookie to clear.
• options is an optional object to match the cookie's path, domain, or other attributes.

Using the same options as when the cookie was set is important to ensure the cookie is properly cleared.

javascript

res.clearCookie('cookieName', { path: '/' });

Example

This example shows a simple Express server that sets a cookie and then clears it when visiting a different route.

javascript

import express from 'express';
const app = express();

app.get('/set', (req, res) => {
  res.cookie('user', 'Alice', { path: '/', maxAge: 900000 });
  res.send('Cookie has been set');
});

app.get('/clear', (req, res) => {
  res.clearCookie('user', { path: '/' });
  res.send('Cookie has been cleared');
});

app.listen(3000, () => {
  console.log('Server running on http://localhost:3000');
});

Output

Server running on http://localhost:3000

Common Pitfalls

Common mistakes when clearing cookies include:

• Not specifying the same path or domain options used when setting the cookie, so the cookie does not get cleared.
• Trying to clear a cookie that was never set or misspelling the cookie name.
• Expecting res.clearCookie() to immediately remove the cookie on the client without a new response.

Always match the cookie options exactly when clearing.

javascript

/* Wrong way: missing path option */
res.clearCookie('user');

/* Right way: include path option if set before */
res.clearCookie('user', { path: '/' });

Quick Reference

Remember these tips when clearing cookies in Express:

• Use res.clearCookie(name, options) with matching options.
• Cookies are cleared by setting expiration to a past date.
• Clearing a cookie sends a Set-Cookie header to the client.
• Check cookie names and paths carefully.

Key Takeaways

Use res.clearCookie('cookieName', options) to clear cookies in Express.

Match the path and domain options used when setting the cookie to clear it properly.

Clearing a cookie sends a response header that tells the browser to remove it.

Always verify the cookie name and options to avoid clearing failures.

res.clearCookie does not delete cookies immediately on the client without a response.