Preview panel: mobile/desktop viewport toggle button is gone

[jameswasher]

Summary

The built-in Preview panel (Cmd+Shift+P, configured via .claude/launch.json) used to have a button in its toolbar to toggle between mobile and desktop viewports. I used it daily for months while iterating on responsive UI. As of a recent version it appears to have been removed — the toolbar now shows only globe/URL, edit, inspect, refresh, and close.

To be clear: this is not the Claude Code Preview Chrome extension — this is the native Preview panel inside the Claude Code desktop app, the one driven by the mcp__Claude_Preview__* tools.

Questions

• Was this toggle intentionally removed? If so, in which version, and is there a tracking issue?
• Is there a setting/flag to bring it back?
• If it's gone for good, is there a recommended replacement workflow for quickly checking mobile breakpoints from inside the IDE?

Why it matters

Toggling viewport from inside the Preview panel made it trivial to verify responsive layouts during a single edit-save loop without alt-tabbing to a separate Chrome window with DevTools open. Losing it adds noticeable friction to any responsive frontend work.

Workaround I'm using now

Opening the dev URL in a separate Chrome window and using DevTools' device toolbar (Cmd+Shift+M). It works but it's a meaningful regression in flow.

Happy to provide a screenshot of the current toolbar if useful.

[jameswasher]

[github-actions]

Found 1 possible duplicate issue:

1. Feature request: device size presets / responsive preview in the Preview window #46269

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🤖 Generated with Claude Code

[jameswasher]

I think that is something different because the button I'm requesting used to be there. It has just disappeared.

[vsohan0701-dotcom]

Yes it is missing for me too, it was really helpful to preview the UI in mobile mode and desktop which really helped making specific changes when need. I really hope they bring it back.

[Eivinj]

what in the devil have they done

[fameracecom]

Confirming on Windows 11 + Claude Code 2.1.138 — same regression. The mobile / tablet / desktop viewport buttons that used to be in the Preview pane toolbar are gone. mcp__Claude_Preview__preview_resize (the MCP tool the agent uses) still works programmatically, but the manual UI control for the human-in-the-loop is missing, so the user can no longer flip viewport themselves while watching the agent work.

This is cross-platform (macOS per the original report + Windows here), which probably points at the Preview pane chrome itself rather than a per-OS rendering issue.

[BenBrussell]

Yeah they really need to bring this back.

[Tuggl3s]

Glad I'm not alone. Used this daily, baffled why it's gone. Hopefully a mistake.