JSR website, JavaScript Registry, jsr.io, TypeScript packages, ESM modules, npm compatibility, Deno, Node.js, Bun, Cloudflare Workers, package publishing, scopes, provenance, and WHOIS domain data

JSR

JSR is a package registry website for modern JavaScript and TypeScript, with jsr.io serving as its public home for package discovery, documentation, publishing, and registry metadata.

Core purpose

JSR hosts JavaScript and TypeScript packages, with a focus on TypeScript source, ECMAScript modules, generated documentation, and cross-runtime use.

Official domain

jsr.io is the official website for browsing packages, reading documentation, signing in, publishing packages, and learning how JSR works.

Domain created

June 28, 2020

The JSR site logo used as the brand image for the website page.View official JSR logo

What JSR is

JSR official site describes JSR as the open-source package registry for modern JavaScript and TypeScript. The website lets developers browse packages, read generated API documentation, sign in with developer accounts, publish packages, and learn how JSR works with JavaScript package managers and runtimes. JSR is built around packages that are published as web-standard ECMAScript modules. It is not presented as a simple replacement for npm; the JSR site describes it as compatible with npm workflows while adding registry behavior designed for TypeScript-first packages.

TypeScript-first packages

JSR is designed to accept TypeScript source directly. The registry can generate API documentation, create TypeScript declaration files, and prepare packages for use across supported environments. That reduces the amount of manual build plumbing maintainers need when they want typed packages to be easy for editors and users to understand.

Publishing and scopes

Packages on JSR use scoped names such as `@scope/package`, and publishing is handled with commands such as `jsr publish` or `deno publish`. A package config file can define metadata, version, and exported entry points, while the website shows package pages with documentation, versions, scores, and installation guidance.

Works across runtimes

JSR documentation describes support for several JavaScript environments, including Node.js, Deno, Bun, browsers, and worker platforms. A project can install a JSR package through runtime-specific commands, supported package managers, or helper commands that add the package to a project using familiar dependency workflows.

Connection to npm

JSR packages are designed to be usable from projects that depend on npm-style package installation. This matters because many JavaScript teams already organize projects around `node_modules`, lockfiles, package manager commands, and CI pipelines that expect npm-compatible dependency layouts.

Who uses JSR

JSR is used by JavaScript and TypeScript library authors, Deno users, Node.js developers experimenting with typed ESM packages, teams targeting multiple runtimes, documentation-heavy package maintainers, and projects that want registry-generated API docs. It is especially relevant to maintainers who want to publish TypeScript source while keeping installation familiar for users.

Why it matters

JSR matters because JavaScript packaging is no longer centered on one runtime or one build style. Modern packages may need to work in Node.js, Deno, Bun, browsers, and edge runtimes while preserving strong TypeScript signals. JSR is one attempt to make that publishing path more direct, better documented, and less dependent on custom transpilation steps.

WHOIS domain data

Data pulled: May 24, 2026View current WHOIS record

Domain: jsr.io
IP address: 172.67.135.174
Registrar: NameCheap, Inc.
WHOIS server: whois.namecheap.com
Referral URL: https://www.namecheap.com/
Created: June 28, 2020
Updated: May 29, 2025
Expires: June 28, 2026
Nameservers: stevie.ns.cloudflare.com (162.159.38.106); eoin.ns.cloudflare.com (162.159.44.86)
Domain status: clientTransferProhibited
Contact privacy: Registrant, admin, and technical contact details are redacted by Privacy service provided by Withheld for Privacy ehf.

Key concepts

RegistryA hosted service that stores package metadata and package releases so projects can discover and install dependencies.
ESMECMAScript modules, the standard JavaScript module format that JSR emphasizes for published packages.
Type declarationsFiles or generated metadata that help TypeScript and editors understand a package's public API.
ScopeThe namespace before a package name, such as `@scope/name`, used to organize package ownership and publishing.

Common workflows

Browse jsr.io to search for packages, read package pages, compare versions, and review generated documentation.
Add a package with Deno, npm-compatible package managers, or helper commands shown in the JSR documentation.
Publish JavaScript or TypeScript ESM packages with package metadata and exported entry points.
Use JSR package pages to inspect docs, scores, licenses, versions, and installation instructions before adopting a dependency.

Common misconceptions

JSR is not only for Deno; its documentation describes use with Node.js, Deno, Bun, browsers, and other environments.
JSR is not just a documentation site; it is a package registry with package publishing, installation, versions, and metadata.
JSR does not remove dependency review; developers still need to evaluate package maintainers, licenses, release history, and security signals.

Open questions

How widely will JavaScript maintainers adopt TypeScript-source publishing instead of prebuilding packages for each target?
How will JSR's compatibility model evolve as npm package managers add or change support for registry protocols?
What trust, provenance, and scoring signals will become most important as more packages target multiple runtimes?