Cookies: Updating a cookie

Join the AI Workshop to learn more about AI and how it can be applied to web development. Next cohort February 1st, 2026

The AI-first Web Development BOOTCAMP cohort starts February 24th, 2026. 10 weeks of intensive training and hands-on projects.


To update the value of a cookie, just assign a new value to the cookie name:

document.cookie = 'name=Flavio2'

Similar to updating the value, to update the expiration date, reassign the value with a new expires or max-age property:

document.cookie = 'name=Flavio; max-age=31536000' //expires in 1 year

Just remember to also add any additional parameters you added in the first place, like path or domain.

Lessons in this unit:

0: Introduction
1: Setting cookies
2: Setting a cookie expiration date
3: Setting a cookie path
4: Setting a cookie domain
5: Cookies security
6: ▶︎ Updating a cookie
7: Deleting a cookie
8: Accessing the value of a cookie
9: Checking if a cookie exists
10: Inspecting cookies
11: Cookie not being set in Safari