Convert JSON object to Buffer and vice versa in Node.js

# Convert JSON object to Buffer and vice versa in Node.js

To convert JSON to a Buffer in Node.js:

Use the JSON.stringify() method to convert the JavaScript object to a JSON string.
Use the Buffer.from() method to convert the JSON string to a buffer.

index.js

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const obj = {
  id: 1,
  name: 'bobby hadz',
  salary: 500,
};

const buf = Buffer.from(JSON.stringify(obj));
// 👇️ <Buffer 7b 22 69 64 22 3a 31 2c 22 6e 61 6d 65 22 3a 22 62 6f 62 62 79 20 68 61 64 7a 22 2c 22 73 61 6c 61 72 79 22 3a 35 30 30 7d>
console.log(buf);

// 👇️ {"id":1,"name":"bobby hadz","salary":500}
console.log(buf.toString());

convert json object to buffer in node js

The code for this article is available on GitHub

The JSON.stringify() method converts a JavaScript value to a JSON string.

index.js

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const obj = {
  id: 1,
  name: 'bobby hadz',
  salary: 500,
};

// 👇️ {"id":1,"name":"bobby hadz","salary":500}
console.log(JSON.stringify(obj));

The Buffer.from method takes the following 2 parameters:

a string - A string to encode.
encoding - The encoding of the string. Defaults to utf8 if not specified.

We didn't specify an encoding and used the default of utf8.

The Buffer.from() method creates a new Buffer that contains the string.

If you need to print the Buffer in a readable format, call the toString() method.

index.js

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const obj = {
  id: 1,
  name: 'bobby hadz',
  salary: 500,
};

const buf = Buffer.from(JSON.stringify(obj));
console.log(buf);

// 👇️ {"id":1,"name":"bobby hadz","salary":500}
console.log(buf.toString());

Buffers store binary data, so in order to print the contents of a buffer in a readable format, we convert the buffer to a string.

# Converting the Buffer back to an object

If you need to convert the Buffer back to an object, use the JSON.parse method.

index.js

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const obj = {
  id: 1,
  name: 'bobby hadz',
  salary: 500,
};

const buf = Buffer.from(JSON.stringify(obj));

// 👇️ convert buffer back to object
const objAgain = JSON.parse(buf);
console.log(objAgain); // 👉️ { id: 1, name: 'bobby hadz', salary: 500 }
console.log(typeof objAgain); // 👉️ object

console.log(objAgain.id); // 👉️ 1
console.log(objAgain.name); // 👉️ bobby hadz
console.log(objAgain.salary); // 👉️ 500

convert buffer back to object

The code for this article is available on GitHub

The JSON.parse() method can be called with a Buffer and converts the buffer to a JavaScript object.

# Converting an Object to a buffer using v8 serialize()

You can also use the serialize() method form the v8 module to convert a JavaScript object to a Node.js Buffer.

However, there is a caveat that the serialize() method comes from the v8 module.

Therefore the Buffer can only be used in Node.js applications.

index.js

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import {serialize, deserialize} from 'v8';

const obj = {
  id: 1,
  name: 'bobby hadz',
  salary: 500,
};

const buf = serialize(obj);
// 👇️ <Buffer ff 0f 6f 22 02 69 64 49 02 22 04 6e 61 6d 65 22 0a 62 6f 62 62 79 20 68 61 64 7a 22 06 73 61 6c 61 72 79 49 e8 07 7b 03>
console.log(buf);

const objAgain = deserialize(buf);

// 👇️ { id: 1, name: 'bobby hadz', salary: 500 }
console.log(objAgain);

convert object to buffer using v8 serialize

The code for this article is available on GitHub

The code sample above uses the ES6 modules import/export syntax.

Use the following import statement if you use CommonJS require().

index.js

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const {serialize, deserialize} = require('v8');

const obj = {
  id: 1,
  name: 'bobby hadz',
  salary: 500,
};

const buf = serialize(obj);
// 👇️ <Buffer ff 0f 6f 22 02 69 64 49 02 22 04 6e 61 6d 65 22 0a 62 6f 62 62 79 20 68 61 64 7a 22 06 73 61 6c 61 72 79 49 e8 07 7b 03>
console.log(buf);

const objAgain = deserialize(buf);

// 👇️ { id: 1, name: 'bobby hadz', salary: 500 }
console.log(objAgain);

The serialize method serializes the supplied value into a buffer.

The deserialize method takes a Buffer that was returned from the serialize() method as a parameter.

The deserialize method reads a JavaScript value from the given Buffer.

Another thing to keep in mind is that you won't get legible results if you call the toString() method on the Buffer.

index.js

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import {serialize, deserialize} from 'v8';

const obj = {
  id: 1,
  name: 'bobby hadz',
  salary: 500,
};

const buf = serialize(obj);

// �o"idI"name"
// bobby hadz"salaryI�{
console.log(buf.toString());

However, this shouldn't be an issue as you can just console.log the deserialized value.

# Converting an Object to a buffer using BSON

You can also use the bson (binary JSON) module to convert an object to a buffer.

index.js

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import {serialize, deserialize} from 'bson';

// or import using CommonJS
// const {serialize, deserialize} = require('bson');

const obj = {
  id: 1,
  name: 'bobby hadz',
  salary: 500,
};

const buf = serialize(obj);
// 👇️ <Buffer ff 0f 6f 22 02 69 64 49 02 22 04 6e 61 6d 65 22 0a 62 6f 62 62 79 20 68 61 64 7a 22 06 73 61 6c 61 72 79 49 e8 07 7b 03>
console.log(buf);

const objAgain = deserialize(buf);

// 👇️ { id: 1, name: 'bobby hadz', salary: 500 }
console.log(objAgain);

The code for this article is available on GitHub

Note that you have to have the bson module installed to be able to run the code sample.

shell

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# with NPM
npm install bson

# or with YARN
yarn add bson

The serialize() method takes an object and returns a Buffer.

The deserialize() method takes a buffer and returns a JavaScript object.

I've also written an article on how to convert a String to a Byte Array in JavaScript.

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Convert JSON object to Buffer and vice versa in Node.js