# jQuery

URL: https://softwaredictionary.org/terms/jquery
Category: Web Development
Last updated: 2026-10-03
Pronunciation: JAY-kweer-ee

In short: jQuery is a JavaScript library that made selecting elements, handling events, animating and making AJAX requests easy with one short, cross-browser syntax.

## What is jQuery?

In the mid-2000s, browsers disagreed on how to do basic things, and the same script often needed different code for Internet Explorer and Firefox. jQuery, created by John Resig, hid those differences behind a small API built around the `$` function: `$(".menu").hide()` found every element with that class and hid it, in any browser.

Its chained style, `$("#form").addClass("active").fadeIn()`, plus helpers for events and AJAX, made front-end work far quicker, and thousands of plugins grew around it. For years it was simply how JavaScript was written on the web, and it is still loaded on a large share of websites, often through WordPress themes and older systems.

Browsers later caught up. Standard features such as `document.querySelectorAll`, `classList`, `fetch` and CSS transitions now cover most of what jQuery offered, and frameworks such as React and Vue changed how interfaces are built: instead of changing the page step by step, they render it from data.

A common misconception is that jQuery is dead or that using it is wrong. It is maintained and perfectly fine for adding small interactions to a server-rendered site or keeping an existing codebase running. For new, complex applications, modern browser APIs or a component framework are usually the better fit.

## Key takeaways

- jQuery is a JavaScript library first released in 2006.
- It smoothed over browser differences with the short $ syntax.
- It made DOM selection, events, animation and AJAX simple.
- Modern browser APIs now cover most of its features.
- It is still common on existing sites, but new apps rarely start with it.

## Example: The same task in jQuery and in plain JavaScript

```javascript
// jQuery
$(".alert").addClass("visible");
$("#save").on("click", () => {
  $.post("/api/save", { title: $("#title").val() });
});

// Modern browser APIs
document.querySelectorAll(".alert").forEach((el) => el.classList.add("visible"));
document.querySelector("#save").addEventListener("click", () => {
  fetch("/api/save", {
    method: "POST",
    body: new URLSearchParams({ title: document.querySelector("#title").value }),
  });
});
```

## Frequently asked questions

**Is jQuery still used?**

Yes, on a very large number of existing websites, especially those built on WordPress and other content management systems. New projects use it much less.

**Should I learn jQuery?**

Learn modern JavaScript and the DOM first. Knowing jQuery's basics helps when maintaining older code, and it is quick to pick up once the fundamentals are clear.

**What replaced jQuery?**

For small tasks, built-in browser APIs such as querySelector, classList and fetch. For larger interfaces, component frameworks such as React, Vue, Angular and Svelte.

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