JavaScript/Wasm feature support #

Our JavaScript and WebAssembly language feature explainers often include feature support listings like the following:

• Chrome: supported since version 71
• Firefox: supported since version 65
• Safari: supported since version 12
• Node.js: supported since version 12
• Babel: supported

A feature without any support would look like this:

• Chrome: no support
• Firefox: no support
• Safari: no support
• Node.js: no support
• Babel: no support

For cutting-edge features, it’s common to see mixed support across environments:

• Chrome: partially supported
• Firefox: supported
• Safari: supported
• Node.js: no support
• Babel: supported

The goal is to provide a quick overview of a feature’s maturity not just in V8 and Chrome, but across the wider JavaScript ecosystem. Note that this is not limited to native implementations in actively-developed JavaScript VMs such as V8, but also includes tooling support, represented using the Babel icon here.

The Babel entry covers various meanings:

• For syntactic language features such as class fields, it refers to transpilation support.
• For language features that are new APIs such as Promise.allSettled, it refers to polyfill support. (Babel offers polyfills through the core-js project.)

The Chrome logo represents V8, Chromium, and any Chromium-based browsers.