Package

array.prototype.flat

An ES2019 spec-compliant `Array.prototype.flat` shim/polyfill/replacement that works as far down as ES3.

v1.3.3, 15 Dec 2024MITCommonJSTypes: NonePolyfills and shims

$ npm install array.prototype.flat

npm GitHub Homepage

Key numbers

As of 25 Sept 2026

Weekly downloads: 54.4m; +67% over 12 months
Gzip bundle size: -; No Bundlephobia data
Dependencies: 4; Direct, from package.json
Last release: 1 year ago; v1.3.3
GitHub stars: 31; 8 forks
Open issues / PRs: 1 / 0
Contributors: 3
Commits, last 52 weeks: 1

Downloads

Last week 2026-09-15 to 2026-09-21

Weekly npm downloads, one point per week, weeks starting 23 Sept 2025 to 15 Sept 2026. The y axis starts at zero.

54,417,229 downloads last week, 247,167,203 in the last month. The 12-month change of +67% compares the average of the last 4 weeks with the first 4 weeks of the series.

Maintenance

Releases, last 12 months: 09 in total
Latest version: 1.3.3, 15 Dec 20241 year ago
First published: 22 May 2018
Last push to GitHub: 30 Dec 2025269 days before the snapshot
Repository archived: No
Open issues: 1
Open pull requests: 0
Commits, last 52 weeks: 1
Dependents on npm: 962

Major versions

v1 first release 1.2.1, 22 May 2018

Recent releases

Version	Published
1.3.3	15 Dec 2024
1.3.2	6 Sept 2023
1.3.1	3 Nov 2022
1.3.0	11 Apr 2022
1.2.5	1 Oct 2021
1.2.4	18 Nov 2020
1.2.3	12 Dec 2019
1.2.2	11 Oct 2019
1.2.1	22 May 2018

Compatibility

Module format: CommonJSFrom package.json type, main and exports fields
TypeScript types: None
Node.js engine range: >= 0.4
Runtimes: -
Unpacked size (npm): 19 kB
Dependencies (4): call-bindes-abstractdefine-propertieses-shim-unscopables

Install

npm install array.prototype.flat

CDN

jsDelivrhttps://cdn.jsdelivr.net/npm/array.prototype.flat@1.3.3/
unpkghttps://unpkg.com/array.prototype.flat@1.3.3/
esm.shhttps://esm.sh/array.prototype.flat@1.3.3

Alternatives

Package	Weekly downloads	Gzip	Last release	Module	Comparison
weakmap-polyfill ECMAScript6 WeakMap polyfill	1m	-	5 years ago	CommonJS	-
object-keys An Object.keys replacement, in case Object.keys is not available. From https://github.com/es-shims/es5-shim	79.8m	-	7 years ago	CommonJS	-
array-buffer-byte-length Get the byte length of an ArrayBuffer, even in engines without a `.byteLength` method.	63.3m	-	1 year ago	CommonJS	-

Sources: npm registry, npm downloads API, GitHub API. Data fetched 25 Sept 2026.

Indexability: Indexed.