Requirements

Item	Version
Unreal Engine	5.7 and 5.8 (both compile-verified on Mac; 5.7.4 tested)
Platforms	Windows 64, macOS
Editor dependency	WebBrowser Widget plugin (bundled with UE5)
Node (for the React side)	20 or higher
Package manager	pnpm 9+ recommended; npm/yarn work
React	18 or higher (peer dep of the SDK)

The plugin itself is a Runtime module — you ship it with your packaged game, not just in-editor.

Mac UE 5.7 / 5.8 caveats

Two engine-level regressions affect macOS Web HUDs.

• Transparent HUD pixels render opaque. Semi-transparent React backgrounds composite as fully opaque on macOS UE 5.7. The same content works on UE 5.6.1. Workaround: design with opaque panels on Mac. See Transparent HUD background.
• Programmatic keyboard focus into CEF is broken. Calling SetFocus from BP does not route OS keystrokes into the embedded browser; one physical click into the input is required to start typing. Confirmed across Slate-focus and window-capture paths. See Chat & keyboard focus.

UE 5.8 status: the transparency regression was hoped fixed in 5.8 — it is not. PIE-tested on UE 5.8.0 (2026-06-25): semi-transparent HUD pixels still composite as opaque (the Slate/Metal compositor still drops CEF surface transparency), same as 5.7. The keyboard-focus regression has not been re-tested on 5.8 — assume still present until confirmed. Plan around both on 5.8 the same as on 5.7.

Windows

Both regressions are macOS-specific (UE 5.7 and 5.8). Windows 64 has neither limitation in our testing.