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JS
Package

is-weakmap

Is this value a JS WeakMap? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

v2.0.2, 8 Mar 2024MITCommonJSTypes: Bundled
$ npm install is-weakmap

Key numbers

As of 25 Sept 2026
Weekly downloads
61m
+90% over 12 months
Gzip bundle size
-
No Bundlephobia data
Dependencies
0
Direct, from package.json
Last release
2 years ago
v2.0.2
GitHub stars
3
2 forks
Open issues / PRs
1 / 0
Contributors
1
Commits, last 52 weeks
1

Downloads

Last week 2026-09-15 to 2026-09-21
025m50m75m100mSept 2025Mar 2026Sept 2026High 81.4m (25 Aug 2026)Low 21.8m (23 Dec 2025)
Weekly npm downloads, one point per week, weeks starting 23 Sept 2025 to 15 Sept 2026. The y axis starts at zero.

61,036,643 downloads last week, 272,068,456 in the last month. The 12-month change of +90% compares the average of the last 4 weeks with the first 4 weeks of the series.

Releases, last 12 months
05 in total
Latest version
2.0.2, 8 Mar 20242 years ago
First published
18 Feb 2015
Last push to GitHub
13 Jan 2026254 days before the snapshot
Repository archived
No
Open issues
1
Open pull requests
0
Commits, last 52 weeks
1
Dependents on npm
648

Major versions

  1. v2 first release 2.0.0, 12 Nov 2019
  2. v1 first release 1.0.0, 18 Feb 2015

Recent releases

VersionPublished
2.0.28 Mar 2024
2.0.118 Dec 2019
2.0.012 Nov 2019
1.0.131 Aug 2015
1.0.018 Feb 2015
Module format
CommonJSFrom package.json type, main and exports fields
TypeScript types
Bundled
Node.js engine range
>= 0.4
Runtimes
-
Unpacked size (npm)
20 kB
Dependencies (0)
None
npm install is-weakmap
  • jsDelivrhttps://cdn.jsdelivr.net/npm/is-weakmap@2.0.2/
  • unpkghttps://unpkg.com/is-weakmap@2.0.2/
  • esm.shhttps://esm.sh/is-weakmap@2.0.2
Sources: npm registry, npm downloads API, GitHub API. Data fetched 25 Sept 2026.

Indexability: Not indexed (discovery only): no category.