# Bun vs JSR

**Leader by vioscaleAI score:** Bun

| Attribute | Bun | JSR |
|---|---|---|
| **vioscaleAI score** | 74.2 (56% (medium)) | 46.5 (42% (low)) |
| activity.commits_last_30d | 100 | 57 |
| adoption.dependent_repos | 21,486 | 0 |
| adoption.github_stars | 96,235 | 2,977 |
| adoption.package_downloads_weekly | 3,990,852 | - |
| content.faq | `[{"answer":"Bun is a JavaScript runtime and development toolkit designed as a fast alternative to Node.js with built-in package management, testing, and bundling capabilities. It can be adopted incrementally into existing Node.js projects or used as a complete replacement for development tooling. It is indexed under Package Registries.","source":"https://bun.sh","question":"What is Bun?","confidence":0.6},{"answer":"Bun offers a free tier, so you can start without paying. Pricing changes often, so verify at source before relying on it.","source":"https://bun.sh","question":"Is Bun free?","confidence":0.6},{"answer":"Bun supports Windows, macOS, Linux and a command-line interface. Platforms we have not confirmed are simply not listed here rather than ruled out.","source":"https://bun.sh","question":"What platforms does Bun support?","confidence":0.6},{"answer":"Yes. Bun can be deployed self-hosted, so it does not have to run on the vendor's infrastructure.","source":"https://bun.sh","question":"Can Bun be self-hosted?","confidence":0.6},{"answer":"Yes. Bun is published under the MIT licence, a permissive licence that generally allows commercial use and modification. Licence terms can change between releases, so verify against the repository for the version you intend to use.","source":"https://www.npmjs.com/package/bun","question":"Is Bun open source?","confidence":0.85}]` | `[{"answer":"An open-source package registry for JavaScript and TypeScript that publishes ECMAScript modules natively. It works across multiple JavaScript runtimes including Node.js, Deno, Bun, and Cloudflare Workers, with built-in TypeScript support, automatic documentation generation, and interoperability with npm packages. It is indexed under Package Registries.","source":"https://jsr.io","question":"What is JSR?","confidence":0.6},{"answer":"JSR is open source, so it can be self-hosted and used at no licence cost. It is released under the MIT licence. Pricing changes often, so verify at source before relying on it.","source":"https://jsr.io","question":"Is JSR free to use?","confidence":0.6},{"answer":"JSR supports the web and a command-line interface. Platforms we have not confirmed are simply not listed here rather than ruled out.","source":"https://jsr.io","question":"What platforms does JSR support?","confidence":0.6},{"answer":"Yes. JSR can be deployed cloud / SaaS and self-hosted, so it does not have to run on the vendor's infrastructure.","source":"https://jsr.io","question":"Can JSR be self-hosted?","confidence":0.6},{"answer":"We have confirmed 6 integrations for JSR, including Node.js, Deno, Bun, Cloudflare Workers, npm and Algolia. This is what we could verify from public sources, so the vendor may support others we have not indexed.","source":"https://jsr.io","question":"What does JSR integrate with?","confidence":0.6},{"answer":"Yes. JSR is published under the MIT licence, a permissive licence that generally allows commercial use and modification. Licence terms can change between releases, so verify against the repository for the version you intend to use.","source":"https://github.com/jsr-io/jsr","question":"Is JSR open source?","confidence":0.95}]` |
| deployment.options | `{"cloud":true,"self_hosted":true}` | `{"cloud":true,"self_hosted":true}` |
| description.long | A JavaScript runtime that executes TypeScript natively using JavaScriptCore, bundling a package manager, bundler, and test runner with Node.js compatibility and npm ecosystem support. | An open-source package registry for JavaScript and TypeScript that publishes ECMAScript modules natively. It works across multiple JavaScript runtimes including Node.js, Deno, Bun, and Cloudflare Workers, with built-in TypeScript support, automatic documentation generation, and interoperability with npm packages. |
| features.capabilities | `{"role":"manager_client","ecosystem":"js","deployment":"cli_local","workspaces":true,"open_source":"oss","pricing_model":"free","upstream_proxy":true,"package_formats":"multi","private_packages":true,"content_addressable":true,"vuln_license_scanning":true,"lockfile_deterministic":true,"supply_chain_integrity":true}` | `{"role":"public_registry","ecosystem":"polyglot","deployment":"saas","open_source":"oss","pricing_model":"free","package_formats":"single","private_packages":true,"supply_chain_integrity":true}` |
| integrations.count | - | 6 |
| integrations.list | - | `[{"name":"Node.js"},{"name":"Deno"},{"name":"Bun"},{"name":"Cloudflare Workers"},{"name":"npm"},{"name":"Algolia"},{"name":"GitHub","native":true}]` |
| language.primary | Rust | Rust |
| license.spdx | MIT | MIT |
| market.availability | - | `{"primaryMarkets":[],"availabilityScope":"global","availableCountries":[],"notAvailableCountries":[]}` |
| platform.support | `{"cli":true,"mac":true,"linux":true,"windows":true}` | `{"web":true}` |
| pricing | `{"type":"open_source","summary":"Free and open source","freeTier":true,"sourceUrl":"https://bun.sh","retrievedAt":"2026-10-14T22:32:45.643Z"}` | `{"type":"free","plans":[{"free":true,"name":"Public","features":["Publish packages","ECMAScript modules","Automatic API documentation","TypeScript support","Cross-runtime compatibility"],"description":"Free public package registry","contactSales":false}],"summary":"Free and open-source","freeTier":true,"sourceUrl":"https://jsr.io","retrievedAt":"2026-08-14T08:31:11.032Z"}` |
| pricing.free_tier | yes | yes |
| pricing.model | open_source | open_source |
| pricing.price_level | free | free |
| pricing.transparent | - | yes |
| release.cadence_days | 14 | - |
| release.history | `[{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.4.3","date":"2026-10-10T05:24:54Z","type":"stable","version":"bun-v1.4.3"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.4.2","date":"2026-09-05T05:55:48Z","type":"stable","version":"bun-v1.4.2"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.4.1","date":"2026-09-04T08:33:19Z","type":"stable","version":"bun-v1.4.1"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.4.0","date":"2026-08-20T14:07:21Z","type":"stable","version":"bun-v1.4.0"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.14","date":"2026-05-13T03:48:28Z","type":"stable","version":"bun-v1.3.14"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.13","date":"2026-04-20T08:07:57Z","type":"stable","version":"bun-v1.3.13"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.12","date":"2026-04-10T03:04:46Z","type":"stable","version":"bun-v1.3.12"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.11","date":"2026-03-18T04:31:40Z","type":"stable","version":"bun-v1.3.11"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.10","date":"2026-02-26T07:08:20Z","type":"stable","version":"bun-v1.3.10"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.9","date":"2026-02-08T09:31:23Z","type":"stable","version":"bun-v1.3.9"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.8","date":"2026-01-29T10:38:16Z","type":"stable","version":"bun-v1.3.8"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.7","date":"2026-01-27T07:04:03Z","type":"stable","version":"bun-v1.3.7"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.6","date":"2026-01-13T02:27:21Z","type":"stable","version":"bun-v1.3.6"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.5","date":"2025-12-17T16:55:41Z","type":"stable","version":"bun-v1.3.5"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.4","date":"2025-12-07T04:53:19Z","type":"stable","version":"bun-v1.3.4"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.3","date":"2025-11-21T19:32:02Z","type":"stable","version":"bun-v1.3.3"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.2","date":"2025-11-08T07:57:10Z","type":"stable","version":"bun-v1.3.2"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.1","date":"2025-10-22T07:53:48Z","type":"stable","version":"bun-v1.3.1"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.3.0","date":"2025-10-10T20:32:14Z","type":"stable","version":"bun-v1.3.0"},{"url":"https://github.com/oven-sh/bun/releases/tag/bun-v1.2.23","date":"2025-09-28T14:23:34Z","type":"stable","version":"bun-v1.2.23"}]` | - |
| security.scorecard | - | 7.3 |
| security.vulnerabilities | `{"count":2,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=npm&package_name=bun&per_page=100","last_12m":0,"max_severity":"HIGH"}` | `{"count":0,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=go&package_name=github.com%2Fjsr-io%2Fjsr&per_page=100","last_12m":0,"max_severity":null}` |

## Capabilities (Package Registries)

| Capability | Bun | JSR |
|---|:--:|:--:|
| **Core** |  |  |
| Role | Package manager client | Public registry |
| **Ecosystem** |  |  |
| Ecosystem / language | JavaScript | Polyglot |
| **Deployment** |  |  |
| Deployment | CLI-local | SaaS |
| **Formats** |  |  |
| Package formats supported | Many formats | Single ecosystem |
| **Hosting** |  |  |
| Private / scoped packages | ✓ | ✓ |
| Upstream proxy / caching | ✓ | - |
| **Resolution** |  |  |
| Lockfile / deterministic installs | ✓ | - |
| Workspaces / monorepo | ✓ | - |
| Content-addressable store | ✓ | - |
| **Supply chain** |  |  |
| Supply-chain integrity | ✓ | ✓ |
| Vulnerability / licence scanning | ✓ | - |
| **Licensing** |  |  |
| Openness | Open-source | Open-source |
| **Pricing** |  |  |
| Pricing model | Free / OSS | Free / OSS |

*Source: vioscaleAI. Generated 2026-10-16T21:49:36.663Z. "-" = undocumented, not absent.*