Cdnjs vs Fastly
A source-aware comparison of pricing, documented capabilities and workflow fit.
Short answer
- Price: not directly comparable — Cdnjs is free, Fastly is usage-based pricing.
- How to start: Cdnjs is free, Fastly is usage-based pricing.
- Where they differ: only Cdnjs has open source / self-hostable and only Fastly has sso (saml); both offer public api.
These lines are generated from the pricing we track, not from a paid placement. How we score tools.
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 Fastly is
Fastly is an edge cloud and CDN with programmable edge compute and very fast cache purging. Instant purge and programmable edge logic are its differentiators: cache invalidation happens in seconds and routing rules run at the edge. It is priced and shaped for teams that treat the CDN as part of the application, not a checkbox.
Side by side
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 Fastly is built to do
- Instant cache purge
- Invalidates cached objects across the network within seconds.
- Edge compute
- Runs custom logic at the edge for routing and personalisation.
- Real-time logging
- Streams request logs to your own systems as they happen.
Choose Cdnjs if
- Sites that want a free public CDN — every file is served from Cloudflare's global network
- Projects at scale: the service reports 250B+ requests per month and use on 12.5% of all websites
- Teams that do not want to self-host popular JavaScript, CSS and font libraries
Skip Cdnjs if
- You need a contractual bandwidth or rate-limit guarantee — none is published
- Your compliance rules forbid loading assets from a third-party network you have no agreement with
- You depend on a sponsor-funded service staying free; funding comes from donated infrastructure
Choose Fastly if
- Teams that need control over caching behaviour at the edge.
Evidence and freshness
Where a claim on this page comes from a vendor page, it is linked here.
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.
Fastly: pros & cons
- Instant global cache purge
- Programmable edge with VCL and Compute
- Strong performance and observability
- Configuration is developer-oriented
- Pricing suits larger traffic volumes
- Steeper learning curve than simple CDNs
Our verdict on Cdnjs
cdnjs is a convenient free path for public, versioned web dependencies; use exact versions and valid SRI, review the library's own license and code, and self-host or provide a fallback when availability, privacy or supply-chain control is critical.
Our verdict on Fastly
Powerful for teams who will use the programmability. Simple static sites do not need it.
Cdnjs vs Fastly: common questions
- Does Cdnjs or Fastly have a free plan?
- Cdnjs has no free plan listed, while Fastly has no free plan listed.
- What is the difference between Cdnjs and Fastly?
- On the criteria we check, only Cdnjs has open source / self-hostable and only Fastly has sso (saml); both offer public api. The table above lists every criterion side by side.