Using node.js, How Do I Read a Json File into (Server) Memory?

Better Stack Team
Updated on April 4, 2024

In Node.js, you can read a JSON file into memory using the built-in fs (File System) module to read the file content and then use JSON.parse to parse the JSON data. Here's a simple example:

const fs = require('fs');

// Specify the path to your JSON file
const filePath = 'path/to/your/file.json';

// Read the JSON file
fs.readFile(filePath, 'utf8', (err, data) => {
  if (err) {
    console.error('Error reading JSON file:', err);

  // Parse the JSON data
  try {
    const jsonData = JSON.parse(data);

    // Now you have the JSON data in memory
    console.log('JSON Data:', jsonData);
  } catch (parseError) {
    console.error('Error parsing JSON:', parseError);


  1. fs.readFile: Reads the content of the file specified by filePath.
  2. 'utf8': Specifies the file encoding. This is important when reading text files.
  3. The callback function is called once the file is read. If there's an error, it's logged. If not, the data is passed to JSON.parse.
  4. JSON.parse: Parses the JSON data into a JavaScript object.

Make sure to replace 'path/to/your/file.json' with the actual path to your JSON file.

Keep in mind that reading files is an asynchronous operation in Node.js, and the callback function is used to handle the results. If you're working with modern JavaScript, you can also use util.promisify or the fs.promises API for a more synchronous-like code structure.

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