What is JSDelivr?

JSDelivr is a special type of content delivery network.
JSDelivr offers mirror for npm, GitHub, WordPress plugins, and custom endpoints for various other projects with specific requirements.

JSDelivr is a free and open-source content delivery network (CDN) that provides fast and reliable access to popular JavaScript libraries and other web assets.

It acts as a central repository for front-end resources and allows developers to easily integrate these resources into their projects by linking to a single URL.

JSDelivr supports a wide range of file types, including JavaScript, CSS, fonts and images, making it a versatile solution for many project types. The platform is community-driven and allows users to contribute their own libraries and assets, making it a comprehensive source of popular front-end resources.

How does JSDelivr work?

JSDelivr is designed to allow users to download JavaScript libraries hosted on npm and Github. JSDelivr is also able to load e.g. WordPress plugins if they are hosted on WordPress.org.

If JSDelivr – or another CDN that offers JavaScript libraries – is used, the source files do not have to be embedded as a copy directly in your own project, but can be outsourced to the CDN.

Why use JSDelivr?

A content delivery network such as JSDelivr improves the performance of a website. The main motivation is to satisfy the visitors of a website with optimal website performance and not to lose any users during the loading process of a website. Because JSDelivr offers numerous possibilities for easy integration, it is a quick option for using a CDN for your own websites.

Advantages of using the JSDelivr CDN

  1. Fast and reliable: JSDelivr makes files available via a global Content Delivery Network (CDN) and offers users around the world fast and reliable access to files.
  2. Easy integration: JSDelivr allows easy integration of popular libraries and other resources by simply linking it to a URL so that developers can easily incorporate these resources into their projects.
  3. Community-driven: JSDelivr is a community-driven platform that allows users to contribute their own libraries and assets, making it a comprehensive source of popular front-end resources.
  4. No maintenance costs: JSDelivr is a free and open source platform, so there are no costs for use or maintenance, which can be especially beneficial for small or personal projects.
  5. Supports multiple file types: JSDelivr supports a variety of file types, including JavaScript, CSS, fonts and images, making it a versatile solution for many types of projects.

Our Rock the Prototype podcast episode on the Artificial Intelligence Act: All the facts about the EU’s AI Act will help you better understand the challenges of IT infrastructure in relation to AI and data protection!

This podcast episode is particularly exciting for anyone interested in infrastructure and technology. It sheds light on how AI and data protection are shaping the digital infrastructure and shows why security standards and regulations – especially in conjunction with tools such as jsDelivr – are so crucial.

Artificial Intelligence Act: Why this podcast episode is relevant for you

  • Insight into European regulations: Understand how the AI Act will influence future technology development.
  • Importance for IT infrastructure: Find out why security and data protection standards in infrastructure are so important.
  • Relevance for jsDelivr: The focus on data protection shows how open source and CDN solutions can be designed to be secure and compliant.

Application examples for JSDelivr in projects

To fully exploit the advantages of JSDelivr, it is worth taking a look at specific use cases:

  • Hosting of JavaScript frameworks: Use JSDelivr to load popular frameworks such as React or Vue directly into your project without having to store them locally.
  • Integration of CSS and font libraries: Load fonts and stylesheets for your website without having to host them yourself.
  • Efficient management of large file inventories: Projects with a lot of media content benefit from the global distribution of JSDelivr, which increases loading time and user-friendliness. These examples show how versatile and flexible JSDelivr can be used for a wide variety of projects!

Security and reliability with JSDelivr

The use of a content delivery network such as JSDelivr not only brings performance advantages, but also security aspects:

  • DDoS protection: Thanks to its distributed structure, JSDelivr offers natural protection against DDoS attacks.
  • Redundancy through multiple server locations: Files are provided from multiple locations worldwide, so that a server failure has hardly any impact on availability.
  • Regular updates: As JSDelivr is updated regularly, the hosted libraries are always up to date and contain important security patches. These factors ensure that your projects not only run quickly, but also securely and stably.

Alternative CDNs compared to JSDelivr

There are several alternatives to JSDelivr that also provide open source libraries and other web assets:

  • CDNJS: Similar to JSDelivr, CDNJS offers an extensive library of resources, but is particularly specialized in JavaScript.
  • Google Hosted Libraries: Google offers its own CDN for popular JavaScript libraries. However, the selection is more limited than with JSDelivr.
  • Microsoft Ajax CDN: Another CDN that is particularly suitable for Microsoft technologies and offers a stable hosting environment. By choosing the right CDN, you can ensure that your project requirements are optimally met – JSDelivr scores particularly well here thanks to its community-driven expandability and versatility.

What jsDelivr can do really well (and what you should use it for)

jsDelivr is strong when you…

  1. want to deliver public, versioned frontend assets from open source sources

  • z. B. vue, htmx, alpine, highlight.js, fonts, CSS, small images

  • Advantage: fast, distributed worldwide, no own infrastructure required

  1. assets that are really “the same for everyone”

  • the file is identical for every user, regardless of login, region, role

  1. you can pin versions

  • i.e. specifically @1.2.3 instead of “any current version”

If your use case looks like this, THEN jsDelivr is a solid choice.

When should you NOT use jsDelivr?

Limit 1: Everything that must not be public

Do not deliver via jsDelivr:

  • internal/privately licensed JS bundles

  • Admin front-ends, back-office tools

  • Customized themes/assets

  • everything that is “only intended for logged-in users”

Why (without buzzwords):

  • jsDelivr is a public CDN – if you deliver it via it, it is in principle publicly accessible.

  • Even if the URL is “unknown”, this is not access protection.

Alternative recommendation:

  • Own hosting (your web server) or private CDN (Cloudflare / Fastly / AWS CloudFront / Azure CDN) with access control.

  • If you want “simple”: put Cloudflare in front of your Origin.

Limit 2: Everything that is personal or user-specific

Not via jsDelivr:

  • Avatars from user accounts

  • Documents, PDFs, uploads

  • Images that only certain roles are allowed to see

  • API responses (of course – but I say it explicitly)

Why:

  • You need access control, possibly tokens, possibly expiration times.

  • A public CDN is not intended for this purpose.

Alternative recommendation (practical):

  • Signed URLs / Signed Cookies in CloudFront/Fastly/Cloudflare

  • Or: Deliver assets via your backend endpoint and cache (if necessary) – but in a controlled manner.

Limit 3: Everything that changes frequently and needs to be up-to-date everywhere immediately

Problem case:

  • you use @latest or “without version spin”,

  • you expect a fix to reach everyone “immediately”.

Why:

  • CDNs cache. “Immediately everywhere” is not the default behavior.

Alternative recommendation:

  • Pin version (@1.2.3) and increase the version for updates.

  • For your own bundles: use content hashing (app.8f3a1c.js) → then every change is automatically a new file name, cache is not an issue.

Limit 4: Everything where you need maximum control over delivery

Examples:

  • you want to globally invalidate, control routing, enforce WAF rules at any time

  • you need special header policies or geo-rules

  • you want to guarantee that only your Origin is considered a source

Why:

  • With a public CDN, you don’t have the same “screwdriver depth” as with your own CDN setup.

Alternative recommendation:

  • Own CDN in front of own Origin (Cloudflare/Fastly/CloudFront)

  • or: host it yourself (and work with good caching)

Limit 5: Everything where you want to minimize supply chain risk (practically formulated)

I don’t call it compliance, I call it that:

If you don’t want an external source to be able to influence your productive code “just like that”, then don’t load libraries live from a public CDN.

Examples:

  • Banking/Health/Enterprise portals

  • Admin panels

  • Critical business flows

Alternative recommendation:

  • Vendor / Bundle: install dependencies via npm, build them into your build (vite/webpack/rollup), deploy them with your app.

  • If you want CDN: your own (CloudFront or similar), but you deliver the files yourself.

Alternatives to JSDelivr

Use jsDelivr for open source assets that may be public and are versioned. As soon as files are protected, personalized or release-critical: Bundle them into your build or deliver them via your own CDN (Cloudflare/CloudFront). But there are also real alternatives to jsDelivr:

Use case A) “I want it simple, but controlled”

✅ Cloudflare before your Origin

  • you host assets yourself (or in the bucket)

  • Cloudflare cached global

  • you retain control

Use case B) “I have many static assets + want standard cloud”

AWS CloudFront + S3 (or Azure CDN + Blob, GCP CDN + Storage)

  • Robust, standardized, great control

  • signed URLs possible

Use Case C) “I am building a WebApp and do not want any external runtime dependencies”

Bundling (Vite/Webpack) + deploy via your app

  • reproducible

  • No “live” CDN dependency

  • Updates come with your release

Use case D) “I need to protect access”

✅ Signed URLs / Token-based Access (CloudFront/Fastly/Cloudflare)

  • Avatars, uploads, PDFs, private media