Node.js zlib.deflateSync() Method Last Updated : 28 Apr, 2025 Suggest changes Share Like Article Like Report The zlib.deflateSync() method is an inbuilt application programming interface of the Zlib module which is used to compress a chunk of data with Deflate. Syntax: zlib.deflateSync( buffer, options ) Parameters: This method accepts two parameters as mentioned above and described below: buffer: This parameter holds the buffer of type Buffer, TypedArray, DataView, ArrayBuffer, and string.options: This parameter holds the value of the zlib option. Return Value: It returns the chunk of data with deflate. The below examples illustrate the use of zlib.deflateSync() method in Node.js: Example 1: javascript // Node.js program to demonstrate the // zlib.deflateSync() method // Including zlib module const zlib = require('zlib'); // Declaring input and assigning // it a value string const input = "GfG CS-Portal"; // Calling deflateSync method const deflated = zlib.deflateSync(input); console.log(deflated); Output: <Buffer 78 9c 73 4f 73 57 70 0e d6 0d c8 2f 2a 49 cc 01 00 1b 48 04 4a> Example 2: javascript // Node.js program to demonstrate the // zlib.deflateSync() method // Including zlib module const zlib = require('zlib'); // Declaring input and assigning // it a value string const input = "GfG CS-Portal"; // Calling deflateSync method and converting // the deflate to string encoded with hex const deflated = zlib.deflateSync(input).toString('hex'); console.log(deflated); Output: 789c734f7357700ed60dc82f2a49cc01001b48044a Reference: https://nodejs.org/api/zlib.html#zlib_zlib_deflatesync_buffer_options N nidhi1352singh Follow Article Tags : Web Technologies Node.js Node.js-Zlib-module Explore Node.js Tutorial 3 min read Introduction & Installation NodeJS Introduction 3 min read Node.js Roadmap: A Complete Guide 6 min read How to Install Node.js on Linux 6 min read How to Install Node.js on Windows 5 min read How to Install NodeJS on MacOS 6 min read Node.js vs Browser - Top Differences That Every Developer Should Know 6 min read NodeJS REPL (READ, EVAL, PRINT, LOOP) 4 min read Explain V8 engine in Node.js 7 min read Node.js Web Application Architecture 3 min read NodeJS Event Loop 5 min read Node.js Modules , Buffer & StreamsNodeJS Modules 5 min read What are Buffers in Node.js ? 4 min read Node.js Streams 4 min read Node.js Asynchronous ProgrammingAsync Await in Node.js 3 min read Promises in NodeJS 7 min read How to Handle Errors in Node.js ? 4 min read Exception Handling in Node.js 3 min read Node.js NPMNodeJS NPM 6 min read Steps to Create and Publish NPM packages 7 min read Introduction to NPM scripts 2 min read Node.js package.json 4 min read What is package-lock.json ? 3 min read Node.js Deployments & CommunicationNode Debugging 2 min read How to Perform Testing in Node.js ? 2 min read Unit Testing of Node.js Application 5 min read NODE_ENV Variables and How to Use Them ? 2 min read Difference Between Development and Production in Node.js 3 min read Best Security Practices in Node.js 4 min read Deploying Node.js Applications 5 min read How to Build a Microservices Architecture with NodeJS 3 min read Node.js with WebAssembly 3 min read Resources & ToolsNode.js Web Server 6 min read Node Exercises, Practice Questions and Solutions 4 min read Node.js Projects 9 min read NodeJS Interview Questions and Answers 15+ min read My Profile ${profileImgHtml} My Profile Edit Profile My Courses Join Community Transactions Logout Like