What it is

Modern.js is a progressive web framework built on React, written in TypeScript and released under the MIT license. It is developed by ByteDance, where it is used to build upper-level frameworks that have supported the development of thousands of web applications. The project lives in the JavaScript and React ecosystem, and it is closely tied to the web-infra-dev family of tools, which includes Rspack, Rsbuild, Rspress and Rslib. The repository has been active for roughly five years, carries about 5,042 stars and 420 forks, and shows 66 open issues.

The concrete problem it addresses is the assembly work that precedes almost every React application. Developers normally have to design an implementation plan for common requirements or pull in separate libraries and frameworks to cover them. Modern.js instead ships all of the configuration and tooling a React application needs, together with additional built-in features and optimizations. A team can build the user interface with React first and then adopt framework features gradually, using them to handle routing, data acquisition and state management as those needs appear.

Key capabilities

• Progressive adoption model: React UI first, then framework features added incrementally for routing, data acquisition and state management.
• Built-in support for all configuration and tools required by React applications, with extra features and optimizations on top.
• Server-side rendering, indicated by the ssr topic in the repository metadata.
• Build tooling rooted in Rspack, the Rust-based web bundler, and Rsbuild, the Rspack-based build tool rebranded from Modern.js Builder.
• Companion ecosystem tools for adjacent jobs: Rspress for static sites and Rslib for library development.
• A published benchmark that tracks bundle size, compile speed and install size over time.
• A collection of ready-to-use examples maintained in the modern-js-examples repository.

Who uses it and how

• ByteDance uses Modern.js as the base for upper-level frameworks that serve thousands of web applications.
• Teams building React applications use it to avoid selecting and wiring separate solutions for routing, data fetching and state.
• Projects that need server-side rendering can adopt the SSR path rather than assembling it themselves.
• Developers who want a starting point can work from the boilerplate and example repositories instead of an empty project.
• Users follow the public roadmap and gather in the project Discord for support and contributions.

Getting started

The README points to the Quick Start guide at modernjs.dev/guides/get-started/quick-start as the entry point. The excerpt does not name a package manager, Docker image or hosted option, so installation specifics come from that guide rather than the repository front page.

When to use it — and when not to

No paid product is named as the thing Modern.js replaces, so the comparison is against assembling a React stack from separate libraries. The README excerpt does not describe a database, storage layer or SMTP service that a self-hoster must operate, and it does not list a hosted offering. The evident weakness is documentation placement: the repository itself carries