# Developer Tools

*noun*

say it: **“dih-VEL-uh-per toolz”** **/dɪˈvɛləpər tuːlz/**

The panels built into a web browser, opened with F12, for inspecting a page's HTML, CSS, scripts and network requests.

## What is **Developer Tools**?

**Developer Tools** — The panels built into every browser, opened with F12. You can inspect any element's HTML and CSS, try style changes live, read errors in the Console and watch every request in the Network tab.

## In a sentence

- “I opened the **developer tools** and saw that my stylesheet wasn't loading.”

Level: Novice · [More Web Development terms at this level](https://www.ask-codey.com/glossary?category=web-development&level=1)

Updated: October 29, 2026

Source: https://www.ask-codey.com/glossary/developer-tools