# is-urlsearchparams

> Determine whether a value is a URLSearchParams instance.

Latest version **2.0.0** (published 2026-08-15) · MIT license · 0 weekly downloads

## Install

```sh
npm install is-urlsearchparams
pnpm add is-urlsearchparams
yarn add is-urlsearchparams
bun add is-urlsearchparams
```

## Health

**Score 60/100 (C)** — status: active.

Positive: esm support; no vulnerabilities; recently updated; high maintenance score.

Warnings: low downloads; no types.

## Facts

| | |
|---|---|
| Version | 2.0.0 |
| Published | 2026-08-15 |
| First published | 2019-01-06 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | none |
| Module format | ESM |
| Node | >= 22 |
| Dependencies | 2 |
| Unpacked size | 9.4 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 2 |
| Author | Steven Vachon |
| Maintainers | stevenvachon |
| Keywords | querystring, searchparams, url, urlsearchparams, whatwg |

## Links

- npm: https://www.npmjs.com/package/is-urlsearchparams
- Repository: https://github.com/stevenvachon/is-urlsearchparams
- Homepage: https://github.com/stevenvachon/is-urlsearchparams#readme
- Issues: https://github.com/stevenvachon/is-urlsearchparams/issues
- npm.io page: https://npm.io/package/is-urlsearchparams

## Dependencies (2)

- [is-object](https://npm.io/package/is-object.md) ^1.0.2
- [has-tostringtag](https://npm.io/package/has-tostringtag.md) ^1.0.2

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## Recent versions

- 2.0.0 (latest) — 2026-08-15
- 2.0.0-rc (rc) — 2026-08-15
- 1.0.2 — 2021-02-27
- 1.0.1 — 2019-04-22
- 1.0.0 — 2019-01-06

## README

# is-urlsearchparams [![NPM Version][npm-image]][npm-url] ![File Size][filesize-image] ![Build Status][ghactions-image] [![Coverage Status][codecov-image]][codecov-url]

> Determine whether a value is a [`URLSearchParams`](https://mdn.io/URLSearchParams) instance.

Works cross-realm/iframe and despite `Symbol.toStringTag`.

> [!NOTE]
>
> If you need to support older versions of Node.js (going back to `8.x`), use `1.x` of this package.

## Install

```shell
npm install is-urlsearchparams
```

## Usage

### Strict

The standard.

```js
import isURLSearchParams from 'is-urlsearchparams';

isURLSearchParams('param=value'); //-> false
isURLSearchParams(new URLSearchParams('param=value')); //-> true
```

### Lenient

Acceptance can be extended to incomplete `URLSearchParams` implementations that lack `entries`, `sort` and `values` methods (which is common with web browsers from 2021):

```js
import isURLSearchParams from 'is-urlsearchparams/lenient';

console.log(params.sort); //-> undefined

isURLSearchParams(params); //-> true
```

[npm-image]: https://img.shields.io/npm/v/is-urlsearchparams
[npm-url]: https://npmjs.com/package/is-urlsearchparams
[filesize-image]: https://img.shields.io/badge/bundle-731B%20gzipped-blue.svg
[ghactions-image]: https://img.shields.io/github/actions/workflow/status/stevenvachon/is-urlsearchparams/test.yml
[codecov-image]: https://img.shields.io/codecov/c/github/stevenvachon/is-urlsearchparams
[codecov-url]: https://app.codecov.io/github/stevenvachon/is-urlsearchparams

---
_Source: https://npm.io/package/is-urlsearchparams · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._