Sec-CH-UA-WoW64 Client Hint

Category: Network / Connectivity
Type: New or changed feature
Status: Proposed (Chrome Proposed)
Intent stage: Start prototyping

Summary

This hint serves solely as a backwards compatible shim for sites relying on "WoW64-ness" (32-bit app running in 64-bit Windows) as they transition from the User-Agent string to UA-CH. It returns a boolean value.

Motivation

We would like to provide a seamless transition from User-Agent-based use cases to UA-CH. The "WoW64" bit is the last piece, and is largely included for backwards compatibility rather than trying to design an API that exposes future binary and OS bitness differences.

Standards & signals

Specification: https://wicg.github.io/ua-client-hints/#sec-ch-ua-wow64
Firefox: No signal
Safari: No signal
Web developers: Mixed signals — We know of at least one site (Meet) that uses wow64.
Tracking bug: https://bugs.chromium.org/p/chromium/issues/detail?id=1288837

Explainers: https://github.com/WICG/ua-client-hints#explainer-reducing-user-agent-granularity

View on chromestatus.com