File preview supports Markdown but not JavaScript or CSS on Windows

Open 💬 0 comments Opened May 23, 2026 by ltz6

What happened?

In the Windows Codex app/CLI environment, file preview works for Markdown files (.md), but JavaScript (.js) and CSS (.css) files do not preview.

Expected behavior

JavaScript and CSS files should open in the preview pane similarly to Markdown files, or the UI should explain that these file types are unsupported.

Actual behavior

Markdown files can be previewed, but attempting to preview .js or .css files does not show a preview.

Environment

  • OS: Microsoft Windows NT 10.0.19045.0
  • Codex: codex-cli 0.130.0-alpha.5
  • GitHub CLI: gh 2.89.0

Additional context

This was observed while using Codex on Windows. Please let me know if logs or a more specific reproduction trace would help.

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