catalog / cross-platform

Inline SVG/HTML visualization is absent on Claude Code

verified

Inline SVG/HTML rendering works on Claude.ai and Desktop but not on Claude Code; skills that emit visualizations there produce raw markup instead of a rendered image.

  • Category: cross-platform
  • Applies to: Claude.ai ✅ | Claude Code ❌ | Claude Desktop ✅
  • Verified on: Claude Code, 2026-05-17
  • Verification tier: verified
  • Severity: Feature gap

Symptom

A SKILL.md that builds diagrams or interactive widgets via visualize:show_widget produces nothing visible on Claude Code. The model likely falls back to ASCII or skips silently.

Cause

Inline SVG/HTML widget rendering (visualize:show_widget family) exists on Claude.ai and Desktop. Claude Code renders CommonMark markdown only — no rendering surface for inline visuals.

Fix

For portable visual output, fall back to markdown tables, ASCII diagrams, or generate SVG/HTML to a file (Write / create_file) and surface it via present_files where present.

Notes

Related: silent-fallback-when-tool-missing.md — the visualization tools are a frequent victim of the silent-fallback pattern.