Introduction ​

WebContainers are a browser-based runtime for executing Node.js applications and operating system commands, entirely inside your browser tab. Apps that previously required cloud VMs to execute user code, in WebContainers can run entirely client-side with a number of benefits over the legacy cloud VM.

WebContainer API is perfect for interactive coding experiences. Among its most common use cases are AI applications, adding in-browser code execution to your existing product, programming tutorials, next-generation documentation, browser based IDEs, and employee onboarding platforms. WebContainers have been battle-tested by millions of users of StackBlitz, and inside the interactive learning environments built by the Svelte, Angular, and Nuxt teams among others.

Key features ​

• Native Node.js inside the browser running Node.js toolchains (for example, Webpack, Vite, and others)
• Flexible: build next-generation coding experiences powered by WebContainers
• Unmatched security: everything is contained in a browser tab
• Fast: spinning up the entire dev environment in milliseconds
• Always free for Open Source: you're the future of the web and we love you 💙

WebContainers versus cloud VM approach ​

WebContainers enables you to build applications that previously required running VMs in the cloud to execute user code. Instead, WebContainers run entirely client-side, providing a number of benefits over the legacy cloud VM approach:

• Unmatched user experience. No latency. Faster than localhost. Works offline.
• Cost effective. Compute is done locally. No paying by the minute for cloud VMs.
• Scales to millions. Leverages modern CDN caching and client-side compute.
• No risk of bad actors. Say goodbyte to bitcoin miners, malware, and phishing sites.

If you want to skip the Quickstart guide and jump stright into exploring the API, you can open the WebContainer starter project in StackBlitz here:

Who's using WebContainers? ​

Initially announced at Google I/O, WebContainers are developed by StackBlitz and have been battle-tested by millions of developers every month as they power the StackBlitz editor. Externally, WebContainers also power a number of popular interactive learning environments including those built by the Svelte, Angular, and Nuxt teams.

To see more examples of how WebContainers have been used so far, check out our Community Projects page.

Get started ​

To get started:

• check out our WebContainer starter
• follow our step-by-step tutorial and build your first WebContainer app
• reading the API reference
• get inspired by our Community projects

Community ​

Wanna ask a question, get some inspiration, or help us amplify your project? Join our Discord community!