The web viewer's 3D viewport renders black on Safari 26.4 (macOS 26 Tahoe and iPadOS 26.4) when WebGPU is the active backend. Other view types (2D, time series, dataframe, etc.) render correctly. Switching to WebGL via "Restart with WebGL" in the viewer menu restores 3D rendering.

This is a regression in Safari 26.4 specifically – Safari 26.3 on iOS still renders 3D correctly under WebGPU. Per caniuse, Safari 26.x is still classified as "Partial support" for WebGPU.

Steps to reproduce

1. On macOS 26.4 Tahoe or iPadOS 26.4 with Safari 26.4, open https://rerun.io/viewer in a new private window.
2. From the welcome screen, open any 3D example (e.g. "URDF").

Expected: the 3D viewport renders normally (as it does on Chrome, Firefox, Safari 26.3, and older Safari versions which use WebGL).

Actual: the 3D viewport is black. No error toast or console errors are surfaced. The rest of the viewer UI renders correctly.

Workaround

In the viewer menu, click "Restart with WebGL". The viewer reloads with WebGL and 3D content renders correctly.

Tested versions

OS	Safari	Result
macOS 26.4.1 Tahoe	26.4 (21624.1.16.11.4)	❌ 3D black
iPadOS 26.4.2	26.4	❌ 3D black
iOS 26.3.1	26.3	✅ works
macOS 15.7.4 Sequoia	18.6	✅ works (defaults to WebGL)

Mitigation in progress

Reverting the default backend to WebGL on Safari while this is broken. Once Apple ships a Safari update that fixes 3D rendering under WebGPU, we can re-enable the WebGPU default.

Related

• WebGPU broken on Safari running on macOS 15 (but works on macOS 26!) #10609 – the predecessor: enabling WebGPU on Safari Tahoe in the first place. That worked on the Safari versions tested at the time; Safari 26.4 has subsequently regressed the 3D pipeline.