---
title: "What is JS Variable?"
url: https://fibr.ai/glossary/js-variable
description: "JavaScript variables store data like user interactions for analytics and tracking, helping marketers collect accurate data and run more effective campaigns."
last_updated: 2026-05-05T11:56:40.410652+00:00
---
A JavaScript (JS) variable stores data on a webpage, such as user interactions or values. Marketers often use them to capture form inputs, clicks, or events for analytics and tracking.

For example, a JS variable might store the number of items added to a cart. This data can then be sent to analytics tools or used for personalization.   
  
Understanding JS variables helps marketers work with developers to collect accurate data and run better tracking campaigns.