How to use querystring in Node.js
Łukasz Holeczek
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Parsing and constructing URL query strings is a common task when building APIs and handling HTTP requests in Node.js applications.
As the creator of CoreUI, a widely used open-source UI library, and with over 11 years of experience in software development, I’ve implemented countless endpoints that require query parameter processing.
The most straightforward approach is using Node.js’s built-in querystring module, which provides simple methods for parsing and stringifying query parameters.
This module handles URL encoding and decoding automatically while maintaining simplicity.
Use the querystring module to parse URL parameters from strings and stringify objects into query strings.
const querystring = require('querystring')
const parsed = querystring.parse('name=John&age=30&active=true')
console.log(parsed) // { name: 'John', age: '30', active: 'true' }
const stringified = querystring.stringify({ page: 1, limit: 10 })
console.log(stringified) // 'page=1&limit=10'
The querystring.parse() method converts a query string into a JavaScript object, automatically handling URL decoding. The querystring.stringify() method does the reverse, converting an object into a properly encoded query string. Both methods handle special characters and encoding automatically, ensuring URL-safe output. Note that all values are treated as strings when parsing.
Best Practice Note:
This is the approach we use in CoreUI’s backend services for handling pagination and filtering parameters. For more complex URL manipulation, consider using the newer URLSearchParams class which provides additional methods and better integration with the modern URL API.
