Claude Preview viewer regression: viewport switcher gone, full URL hidden behind click

Regression report — Claude Preview viewer (v2.1.138 on Windows)

Two pieces of the Claude Preview viewer header have regressed in a recent release. Both worked fine previously and the change appears undocumented in the changelog.

1. Mobile / Tablet / Desktop viewport switcher is gone

The Preview viewer used to render a visible viewport switcher (mobile / tablet / desktop preset buttons) in the viewer header. It's no longer there.

The underlying capability (mcp__Claude_Preview__preview_resize MCP tool with presets mobile 375x812, tablet 768x1024, desktop 1280x800) still works fine when the agent loads it via ToolSearch and calls it — but the viewer's UI no longer surfaces the switcher buttons. So if the agent doesn't explicitly load preview_resize, the user loses access to the switcher from the UI entirely. Previously the switcher was always visible regardless of which tools were loaded.

2. Full URL of the previewed page is hidden behind a click

The viewer used to display the full URL of the currently-loaded preview page inline in the header at all times. Now it's collapsed/truncated and the user has to click to expand and see the full URL.

This is a daily-friction regression — when you're QAing or following deeplinks across multiple routes, having the URL visible at a glance is essential to knowing which page you're looking at. Hiding it behind a click breaks "scan the screen → understand what you're looking at" flow.

Environment

• Claude Code version: 2.1.138
• Platform: Windows 11 (Git Bash)
• Preview viewer in use via mcp__Claude_Preview__* tools (preview_start, preview_screenshot, preview_resize, etc.)

Requested fix

Either:

• Restore the previous default — viewport switcher always visible in viewer header, full URL displayed inline at all times. (Preferred.)
• Or add explicit toggles in ~/.claude/settings.json (e.g. previewViewer.showViewportSwitcher: true, previewViewer.showFullUrlInline: true) so users can opt back in.

No undocumented hardcoded UX removal of features that were previously default-on. This is a power-user surface and removing visible affordances costs daily productivity.

Thanks!