Node.js os.freemem() Method

Last Updated : 28 Apr, 2025

The os.freemem() method is an inbuilt application programming interface of the os module which is used to get the amount of free system memory. 

Syntax:

os.freemem()

Parameters: This method does not accept any parameters. 

Return Value: This method returns an integer value that specifies the amount of free system memory in bytes. 

Example 1: The below example illustrates the use of os.freemem() method in Node.js: 

javascript 
// Node.js program to demonstrate the
// os.freemem() method

// Allocating os module
const os = require('os');

// Printing os.freemem() value
console.log(os.freemem());

Output:

4158910464

Example 2: The below example illustrates the use of os.freemem() method in Node.js: 

javascript 
// Node.js program to demonstrate the
// os.freemem() method

// Allocating os module
const os = require('os');

// Printing os.freemem() value
const free_memory = os.freemem();
const free_mem_in_kb = free_memory / 1024;
const free_mem_in_mb = free_mem_in_kb / 1024;
const free_mem_in_gb = free_mem_in_mb / 1024;

free_mem_in_kb = Math.floor(free_mem_in_kb);
free_mem_in_mb = Math.floor(free_mem_in_mb);
free_mem_in_gb = Math.floor(free_mem_in_gb);

free_mem_in_mb = free_mem_in_mb % 1024;
free_mem_in_kb = free_mem_in_kb % 1024;
free_memory = free_memory % 1024;

console.log("Free memory: " + free_mem_in_gb + "GB "
    + free_mem_in_mb + "MB " + free_mem_in_kb
    + "KB and " + free_memory + "Bytes");

Output:

Free memory: 4GB 110MB 88KB and 0Bytes

Note: The above program will compile and run by using the node index.js command. 

Reference: https://nodejs.org/api/os.html#os_os_freemem

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