esnext

ESNext is an informal term used to describe the set of JavaScript language features and syntax that are proposed for inclusion in the ECMAScript standard but have not yet been finalized in a published edition. It functions as a moving target for developers and tooling, signaling features that may become part of future ECMAScript releases.

The evolution of ESNext is driven by TC39, the committee that stewardes the ECMAScript specification. Proposals move through stages from 0 to 4, with Stage 4 indicating formal adoption into the standard. Features labeled ESNext may be in various stages of development and are subject to change before they appear in a stable ECMAScript edition. Because of this, implementers and tooling often track ESNext to stay aligned with upcoming changes.

In practice, ESNext features are typically made available to developers through transpilers and polyfills. Tools like Babel, TypeScript, and SWC translate newer syntax into established JavaScript that runs in current environments, while runtime engines in browsers and Node.js gradually adopt supported features. This ecosystem allows developers to experiment with upcoming syntax without sacrificing compatibility.

Commonly discussed ESNext proposals include enhancements such as optional chaining, nullish coalescing, dynamic import, import.meta, private class fields, Top-Level Await, and other language refinements. While some of these have later become standard, others may still be evolving. The term ESNext therefore serves as a shorthand for the ongoing forward-looking frontier of JavaScript language design, rather than a specific, official version.