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WinterJS

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Blazing-fast JavaScript server for Service Workers, built for high performance.

Developer ToolsHosting & DeploymentEdge Computing
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Tracked since2026
0 reviews tracked

The Bottom Line

Entry price

Free, no paid tier

Biggest pro

Extremely high performance for JavaScript server-side applications

Biggest con

Building from source requires complex steps, including SpiderMonkey compilation

TL;DR - WinterJS

  • A blazing-fast JavaScript server running WinterCG-compliant Service Workers.
  • Achieves high performance, handling up to 100,000 requests/second.
  • Built with SpiderMonkey, Spiderfire, and Hyper, with WASIX support.
Pricing: Free forever
Best for: Individuals & startups

What is WinterJS?

Editorial review
WinterJS is a high-performance JavaScript server designed to run Service Worker scripts according to the Winter Community Group (WinterCG) specification. It leverages SpiderMonkey, Spiderfire, and Hyper to achieve exceptional speed, capable of handling up to 100,000 requests per second on a single laptop. This makes it ideal for developers building server-side applications that require high throughput and low latency, particularly those familiar with or looking to utilize the Service Worker API on the server. The product is geared towards developers who need a robust and efficient JavaScript runtime for server-side logic, especially in environments where WebAssembly (WASM) compilation is beneficial. While it supports WASIX for WebAssembly compilation, the project recommends using precompiled versions for simplicity. WinterJS aims to provide a fully compliant WinterCG runtime, offering a familiar environment for web developers extending their skills to the backend.

Available on: Web, macOS, Linux

how we evaluateSourcewinterjs.org ↗

Pros & Cons

Pros

  • Extremely high performance for JavaScript server-side applications
  • Compliance with WinterCG specification provides a standardized environment
  • Leverages established and performant technologies like SpiderMonkey and Hyper
  • Open-source with an MIT license
  • Supports a wide range of standard web APIs for server-side use

Cons

  • Building from source requires complex steps, including SpiderMonkey compilation
  • WASIX compilation is currently a complex process
  • Some APIs are partially implemented or pending, indicating ongoing development

Preview

Key Features

WinterCG specification complianceHigh-performance HTTP server (100,000 reqs/s)SpiderMonkey JavaScript engine integrationSpiderfire and Hyper for underlying architectureWASIX standard for WebAssembly compilationSupports `fetch`, `Response`, `Request`, `URL`, `Headers`Includes `console`, `performance`, `crypto` APIsSupports `ReadableStream`, `WritableStream`, `TransformStream`

Pricing

Free

WinterJS is completely free to use with no hidden costs.

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WinterJS FAQ

What is WinterJS?

WinterJS is a blazing-fast JavaScript server that executes Service Worker scripts in accordance with the Winter Community Group (WinterCG) specification. It's designed for high performance, capable of handling a large number of requests per second.

How much does WinterJS cost?

WinterJS is open-source and available under the MIT license, meaning it is free to use.

Is WinterJS free?

Yes, WinterJS is completely free as it is an open-source project licensed under MIT.

Who is WinterJS for?

WinterJS is for developers who need a high-performance JavaScript runtime for server-side applications, particularly those interested in using Service Worker APIs on the server or building applications that require high throughput and low latency. It's also suitable for developers looking to compile JavaScript to WebAssembly using WASIX.

Source: winterjs.org

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