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How to Fetch Data From an API in ReactJS?

Last Updated : 19 Apr, 2025
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ReactJS provides several ways to interact with APIs, allowing you to retrieve data from the server and display it in your application. In this article, we’ll walk you through different methods to fetch data from an API in ReactJS, including using the built-in fetch method, axios, and managing the state effectively.

1. Using JavaScript fetch() method

The fetch() method in JavaScript is used to make network requests (such as HTTP requests) and fetch data from a specified URL. It returns a Promise that resolves to the Response object representing the response to the request.

CSS
/* App.css*/ 
.App {
    text-align: center;
    /* color: Green; */
}
.container {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
}

.item {
    min-width: 33rem;
    text-align: left;
}

.geeks {
    color: green;
}
JavaScript
import React, { useState, useEffect } from "react";
import "./App.css";

const App = () => {
    const [items, setItems] = useState([]);
    const [dataIsLoaded, setDataIsLoaded] = useState(false);

    useEffect(() => {
        fetch("https://jsonplaceholder.typicode.com/users")
            .then((res) => res.json())
            .then((json) => {
                setItems(json);
                setDataIsLoaded(true);
            });
    }, []); 

    if (!dataIsLoaded) {
        return (
            <div>
                <h1>Please wait some time....</h1>
            </div>
        );
    }

    return (
        <div className="App">
            <h1 className="geeks">GeeksforGeeks</h1>
            <h3>Fetch data from an API in React</h3>
            <div className="container">
                {items.map((item) => (
                    <div className="item" key={item.id}>
                        <ol>
                            <div>
                                <strong>User_Name: </strong>
                                {item.username},
                            </div>
                            <div>Full_Name: {item.name}</div>
                            <div>User_Email: {item.email}</div>
                        </ol>
                    </div>
                ))}
            </div>
        </div>
    );
};

export default App;

OutputPeek-2023-10-05-17-33

In this example

  • This React component fetches data from an API using the fetch method inside componentDidMount().
  • It stores the fetched data in the state and displays the user’s username, name, and email once the data is loaded.
  • If the data is still loading, it shows a “Please wait” message.

2. Using axios library

Axios library is a popular, promise-based JavaScript library used to make HTTP requests from the browser or NodeJS. It simplifies making requests to APIs, handling responses, and managing errors compared to the native fetch() method.

Install Axios library using the following command

npm i axios

The updated dependencies in the package.json file are:

"dependencies": {
"@testing-library/jest-dom": "^5.17.0",
"@testing-library/react": "^13.4.0",
"@testing-library/user-event": "^13.5.0",
"react": "^18.3.1",
"react-dom": "^18.3.1",
"axios": "^1.5.0",
"react-scripts": "5.0.1",
"web-vitals": "^2.1.4"
},
CSS
/* App.css*/ 
.App {
    text-align: center;
    /* color: Green; */
}
.container {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
}

.item {
    min-width: 33rem;
    text-align: left;
}

.geeks {
    color: green;
}
JavaScript
// App.js
import React, { useState, useEffect } from "react";
import "./App.css";
import axios from "axios";

const App = () => {
    const [items, setItems] = useState([]);
    const [dataIsLoaded, setDataIsLoaded] = useState(false);

    useEffect(() => {
        axios
            .get("https://jsonplaceholder.typicode.com/users")
            .then((res) => {
                setItems(res.data);
                setDataIsLoaded(true);
            });
    }, []);

    if (!dataIsLoaded) {
        return (
            <div>
                <h1>Please wait some time....</h1>
            </div>
        );
    }

    return (
        <div className="App">
            <h1 className="geeks">GeeksforGeeks</h1>
            <h3>Fetch data from an API in React</h3>
            <div className="container">
                {items.map((item) => (
                    <div className="item" key={item.id}>
                        <ol>
                            <div>
                                <strong>User_Name: </strong>
                                {item.username},
                            </div>
                            <div>Full_Name: {item.name}</div>
                            <div>User_Email: {item.email}</div>
                        </ol>
                    </div>
                ))}
            </div>
        </div>
    );
};

export default App;

Output

Peek-2023-10-05-17-33

In this code

  • This React component uses Axios to fetch data from an API when the component mounts.
  • It stores the fetched data in the state and displays the users’ username, name, and email once the data is loaded.
  • If the data is not loaded, it shows a loading message.

3. Using the Stale-While-Revalidate (SWR) Method

SWR is a data-fetching library developed by Vercel that makes it easy to fetch and cache data in React applications. The concept behind SWR is simple: fetch data, use stale data for immediate UI rendering, and revalidate it in the background to get fresh data.

Steps to Install SWR

npm install swr
JavaScript
import React from 'react';
import useSWR from 'swr';

const fetcher = (url) => fetch(url).then((res) => res.json());

const App = () => {
    const { data, error } = useSWR('https://jsonplaceholder.typicode.com/users', fetcher);

    if (error) return <p>Error loading data</p>;
    if (!data) return <p>Loading...</p>;

    return (
        <div>
            <ul>
                {data.map((user) => (
                    <li key={user.id}>
                        <h3>{user.username}</h3>
                        <p>{user.name}</p>
                        <p>{user.email}</p>
                    </li>
                ))}
            </ul>
        </div>
    );
};

export default App;

Output

SWR-1

Fetch Data From an API in ReactJS

In this code

  • SWR automatically handles caching, background revalidation, and state management for data fetching.
  • The useSWR hook fetches the data and handles the logic for loading, error, and success states.
  • It provides an automatic re-fetching of data if the component re-renders or if the data becomes stale.

4. Using the React Query Library

React Query is another powerful library that simplifies data fetching, caching, synchronization, and more. It is great for applications where the data changes frequently and you need efficient, real-time data fetching with minimal boilerplate.

Steps to Install React Query

npm install react-query
App.js
import React from 'react';
import { useQuery } from 'react-query';

// Function to fetch data
const fetchUsers = async () => {
    const res = await fetch('https://jsonplaceholder.typicode.com/users');
    if (!res.ok) throw new Error('Network error');
    return res.json();
};

const App = () => {
    // Use useQuery to fetch data
    const { data, error, isLoading } = useQuery('users', fetchUsers);

    if (isLoading) return <p>Loading...</p>;
    if (error) return <p>Error loading data</p>;

    return (
        <div>
            <h1>User List</h1>
            <ul>
                {data.map((user) => (
                    <li key={user.id}>
                        <h3>{user.username}</h3>
                        <p>{user.name}</p>
                        <p>{user.email}</p>
                    </li>
                ))}
            </ul>
        </div>
    );
};

export default App;
QueryClient.js
import React from 'react';
import { QueryClient, QueryClientProvider } from 'react-query';
import App from './App';

const queryClient = new QueryClient();

function Root() {
    return (
        <QueryClientProvider client={queryClient}>
            <App />
        </QueryClientProvider>
    );
}

export default Root;

Output

SWR-4

Fetch Data From an API in ReactJS

In this code

  • React Query’s useQuery hook is used to fetch data and manage state.
  • It automatically handles caching, background refetching, and error handling.
  • If the data is still loading, it shows a loading message. If there’s an error, it displays an error message.

Conclusion

Fetching data from an API is a critical task in modern web applications, and both fetch() and Axios are widely used methods for achieving this in React. Use fetch() if you prefer a native, lightweight solution for making HTTP requests in your React apps. Use Axios for more features like automatic JSON parsing, improved error handling, and a cleaner syntax for HTTP requests.



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