frontend (FE)

basicwidespread

The frontend is the part of a website or application that you see and use: buttons, menus, forms, and everything that appears on your screen.

In plain terms

Think of a restaurant. The dining area with tables, the menu, and the waiter is the frontend: this is where you sit, order, and see. The kitchen, where the food is prepared, is the backend. You cannot see into the kitchen from the dining area, but together they make up the restaurant.

The frontend's job is to make the program understandable and comfortable. This includes where the button is, how large the font is, what happens when you click something, and whether the same page works well on a phone.

The frontend usually runs on your device, meaning in your browser or on your phone. The backend, by contrast, works on remote servers, where data is stored and important decisions are made, such as whether you can log in.

The same applies to AI tools. The chat window where you type your question is the frontend. The language model and the agent working in the background are not.

How it works

You enter a web address, and your device downloads the interface description from the server; with installed applications, most of the interface is already on your phone or computer.
The browser assembles these three elements: HTML provides the page structure, CSS the appearance, and JavaScript the behavior.
When you click, type, or scroll, the frontend reacts instantly: opening a menu, validating a form, or animating.
If data is needed (for example, your account balance or search results), the frontend sends a request to the backend via an API.
The response arrives, and the frontend displays it in a readable format, often without requiring a full page reload.

An everyday example

You open your online banking on your phone: the login screen, the card showing your balance, and the "Transfer" button are all part of the frontend. When you press the button, the frontend sends your request to the bank's servers, and the transfer takes place there, in the backend.

Who is affected

everyoneYou use every website and application through its frontend, so your ability to navigate it depends on the quality of that frontend.

developerFrontend development is an independent profession where coding agents now handle much routine work. → Code

entrepreneur, executiveYour customer judges your company based on the frontend, and a slow or confusing interface causes them to leave quickly.

jobseeker, new graduateFrontend is a common entry point to the programming career because your work's result is immediately visible on the screen. → Work & HR

A common misconception

MythFrontend is just design, meaning selecting colors and fonts.

In realityFrontend programming: the designer plans how the interface should look, while the frontend developer writes code to make it functional. Speed, accessibility, and handling different screen sizes are also their responsibility.

Limits and risks

What runs on the frontend runs on your device, so a knowledgeable person can inspect and rewrite it; true security checks must occur in the backend.
A nice interface does not prove the service is reliable: phishing sites copy the frontends of banks and online shops.
The same page may behave differently in various browsers, on an old phone, or with slow internet.
With AI, you can create a striking interface in minutes, but this does not mean a functional, secure system exists behind it.

Similar, but not the same

backend – The backend is the part running in the background on servers, storing data and enforcing rules; you never see this directly.
user interface (UI) – The user interface is what you see on the screen, while the frontend is the code and technology that displays and operates it.
web design – Web design is the planning of the interface, while frontend development is the implementation of that plan as a working program.

Related concepts

Broader

software development, web development, Application

Narrower

HTML, CSS, JavaScript, responsive design

On the edge

backend, full stack, API, user interface, user experience

A brief history

HTML, the markup language for web pages, emerged in the early 1990s through the work of Tim Berners-Lee, while JavaScript appeared in 1995 in the Netscape browser. As web pages became increasingly complex, the development of the interface and the backend system gradually split into two separate fields.

Where things stand

Frontend is an established basic concept in software development and a field of its own. As of late 2026, coding agents can already produce a working interface from a text description, but checking quality, security and accessibility is still a human task.

Status: 2026 November

Also known as

frontend · front-end · front end · FE · kliensoldal · client-side · frontend development

Sources

MDN Web Docs: Learn web development

This entry was machine-edited and has undergone machine expert review; the “In the news” section updates automatically from Agent Age stories.