How to Install a Codex Theme on Windows (Step by Step)

To install a Codex theme on Windows, use the OpenAI Codex desktop app, install Node.js 20 or later, then ask Codex to install the open-source GptSkin Skill. Apply a free preset first so you can verify the complete workflow without creating an account.

Before You Start

This guide is for the Codex desktop app on Windows, which OpenAI announced for Windows in March 2026. It is not for Codex CLI or the VS Code extension.

Open PowerShell and confirm Node.js:

node -v

The result must be version 20 or later. You also need Git only if you choose the manual installation route.

Step 1: Install GptSkin from Codex

Open a Codex task and send:

Install this skill and give Codex a new look: https://github.com/WendongAI/gptskin-skill

Codex can clone the public repository, install its dependencies, and explain what it changed. Restart Codex when the installation completes.

Step 2: Apply a Free Theme

In Codex, say:

Apply the dark-void preset theme

Or run this in PowerShell:

node "$HOME/.codex/skills/gptskin-theme/scripts/apply-theme.mjs" --preset dark-void

No GptSkin account is required for presets. Preview Dark Void or compare the best dark Codex themes.

Step 3: Verify the Result

Check that the sidebar, thread area, composer, buttons, and code remain readable. If nothing changes, restart Codex, update the Skill, and apply the preset again:

git -C "$HOME/.codex/skills/gptskin-theme" pull
node "$HOME/.codex/skills/gptskin-theme/scripts/apply-theme.mjs" --preset dark-void

Step 4: Use Your Own Image (Optional)

Custom image themes require a GptSkin account and 20 Credits per new theme. JPEG, PNG, and WebP files up to 4 MiB are supported. The Skill opens browser authorization; you never paste an API key into it. Follow how to create a Codex theme from an image for that workflow.

Restore the Default Theme

Tell Codex Restore the default Codex theme. GptSkin removes its runtime styling and starts Codex normally. It does not modify the official package, app.asar, code signatures, your API key, or conversations.

Windows Troubleshooting

For the complete safety boundary, see security architecture. GptSkin is independent and is not affiliated with or endorsed by OpenAI.