Cdnjs vs JSDelivr

What Cdnjs is

cdnjs is a free, community-run CDN for open-source web-library assets, delivered through Cloudflare. Consumers select a library, exact version and file, then reference its public URL; the service also exposes library metadata through an API. Example markup published by Cloudflare uses a versioned URL and Subresource Integrity attributes. cdnjs' code repository is MIT-licensed, but each distributed library keeps its own license. It is a dependency-delivery service rather than private storage, a package-security review or a contractual availability guarantee.

What JSDelivr is

jsDelivr is a publicly available CDN for open-source files from npm, GitHub, WordPress and selected custom endpoints. Its terms permit free personal and commercial use without bandwidth or request limits when content and usage follow both jsDelivr and upstream-platform policies. The network uses multiple CDN providers and offers exact or aliased version URLs, an API, combination and optimization features. Production consumers should pin an exact reviewed release: aliases can resolve to newer code. The service is not general file/media hosting, private package delivery or a substitute for package, license and resilience review.

What Cdnjs is built to do

Library catalog

Indexes versioned files from supported open-source JavaScript and CSS libraries.

Cloudflare delivery

Serves cached public assets through Cloudflare's network.

API access

Exposes library, version and file metadata for discovery and tooling.

Integrity-ready snippets

Provides examples and hashes that can be used with browser SRI and crossorigin attributes.

What JSDelivr is built to do

Public package endpoints

Serves files from npm, GitHub, WordPress and approved custom open-source sources.

Multi-CDN routing

Uses multiple providers and monitoring-based failover for public asset delivery.

Version selection

Supports exact releases and convenient aliases; exact pins are safer for reproducible production builds.

Package API

Returns versions, files, entry points, CDN links and download statistics for tooling.

Choose Cdnjs if

• Static sites loading a well-known public library at an exact reviewed version
• Documentation and prototypes where a third-party CDN is permitted
• Teams that enforce CSP, verify SRI hashes and retain a self-hosted fallback for critical assets

Skip Cdnjs if

• Assets are private, proprietary or outside the cdnjs library catalog
• Policy forbids third-party asset requests or requires a contractual SLA
• The team cannot review the package license and code or pin an immutable version

Choose JSDelivr if

• Public npm or GitHub packages that need zero-cost global asset delivery
• Static sites using exact reviewed dependency versions
• Open-source maintainers who want public package metadata and download statistics

Skip JSDelivr if

• The workload is proprietary, private, general-purpose storage or large-scale media hosting
• The application requires negotiated uptime and support-response commitments
• Security policy cannot allow a third-party domain or the build cannot pin and review dependencies

Cdnjs: pros & cons

• No-cost public delivery: Supported open-source library assets are served globally through Cloudflare.
• Versioned paths: URLs can identify an exact library release and file for reproducible front-end loading.
• Integrity metadata: Published examples support browser Subresource Integrity checks when the correct hash is used.
• Open project and API: Public repositories and metadata endpoints make the catalog inspectable and automatable.
• Catalog scope is narrow: It is not private asset storage or a general-purpose origin/CDN product.
• Package trust remains external: CDN availability does not prove that a library release or transitive code is safe.
• Third-party dependency: Page delivery, privacy posture and CSP must account for requests to an external domain.
• Licenses vary: The cdnjs repository license does not replace the license of each hosted library.

JSDelivr: pros & cons

• Free permitted use: The published terms allow personal and commercial use without request or bandwidth limits.
• Broad public-package access: npm, GitHub and WordPress paths cover common open-source distribution workflows.
• Resilient delivery design: Multiple CDN and DNS providers plus health-based routing reduce dependence on one edge network.
• Developer tooling: Public APIs expose package versions, files, entry points, CDN URLs and download statistics.
• Strict usage scope: General image, video, backup or bulk file hosting is prohibited.
• Mutable aliases add risk: Unpinned version ranges or latest URLs can deliver code different from a reviewed build.
• Upstream rules still apply: Content must satisfy npm, GitHub or other source-platform terms as well as jsDelivr's policy.
• Free support is limited: Published terms promise a reasonable level of issue/email support, not a customer-specific response SLA.