Can You Theme the ChatGPT Desktop App?

Updated: August 5, 2026 · 5-minute read

Written and maintained by the Chroma AI team at ComfortOne Co., Ltd. — we build the extension this guide describes, and we update these pages as the interfaces change.

This is one of the most common questions we get: "I use the ChatGPT desktop app — can I theme that too?" The honest answer is no, and it's worth explaining why, because the reason isn't a missing feature. There's also a straightforward workaround that gets you a desktop-style window and full customization, and it takes about a minute to set up.

Why no extension can theme a desktop app

Browser extensions run inside the browser. When you install one, the browser grants it permission to read and modify pages loaded in its own tabs. That's the entire scope of what an extension is allowed to touch.

A desktop app is a separate program with its own window, its own process and its own files. Your browser has no relationship with it, so there is no mechanism for an extension to style it. This isn't specific to Chroma AI — no browser extension can theme any desktop application, and any tool claiming otherwise is doing something quite different (and riskier) under the hood.

What "something riskier" means

It is technically possible to modify some desktop apps by unpacking and rewriting their program files. We've looked at it seriously and decided against it, for reasons worth knowing if you come across a tool that does:

• It breaks code signing. Apps are cryptographically signed so your operating system can verify they haven't been tampered with. Editing the app's files invalidates that signature — which is exactly the signal your OS uses to detect malware.
• Every app update wipes it. These apps update frequently and replace their own program files when they do, so any modification disappears silently and has to be reapplied.
• Antivirus flags it. A program whose job is to modify another program's files looks, to a security scanner, exactly like something you don't want on your machine.
• It likely violates the terms of service. Modifying client software is usually prohibited outright, which is a different legal question from restyling a web page you're viewing.

We'd rather do one thing safely than everything precariously. Restyling a web page in your own browser is well within what browsers are designed to allow; rewriting someone's application binary is not.

The workaround: install the web version as an app

Here's the part most people don't know. Chrome and Edge can install a website as a standalone app window — its own icon in the taskbar or Dock, no address bar, no tabs, alt-tab like any other program. It looks and feels like a desktop app.

And critically: it's still the browser engine underneath, so your extensions keep working. Content scripts run normally in an installed app window.

So you get the desktop experience you wanted and your themes.

Installing it (about one minute)

1. Open chatgpt.com (or claude.ai / gemini.google.com) in Chrome or Edge.
2. Click the install icon in the address bar — a small monitor-with-arrow symbol on the right side. If you don't see it, open the browser's ⋮ menu and look for Cast, save and share → Install page as app (Chrome) or Apps → Install this site as an app (Edge).
3. Confirm the name and click Install.
4. The app opens in its own window and gets an icon you can pin to your taskbar, Start menu or Dock.

Opening the sidebar inside the app window

One difference: an app window doesn't show the extension toolbar, so you can't click the Chroma AI icon the usual way. Two options:

• Keyboard shortcut — press Ctrl + Shift + E (⌘ + Shift + E on macOS). This is the fastest route and works anywhere the extension is active.
• Extensions menu — click the ⋮ or puzzle-piece button in the app window's title bar and choose Chroma AI from the list.

Set your theme once and it persists — you won't need the sidebar again until you want to change something.

What you gain and what you give up

The main thing you give up is the deeper OS integration some official apps offer — system-wide shortcuts, certain file handling. If you rely on those, keep the official app. If what you wanted was "a dedicated window that isn't lost among thirty tabs," the installed web app gives you that plus everything the browser can do.

Which platforms this works for

• ChatGPT — installs cleanly as an app from chatgpt.com in Chrome or Edge.
• Claude — same, from claude.ai.
• Gemini — same, from gemini.google.com.

All three keep their own separate theme settings in Chroma AI, so you can give each window a distinct look and tell them apart instantly when switching.

Frequently asked questions

Related guides

• Using Chroma AI on Edge, Brave and Opera
• Set up an AI chat workspace for all-day use
• How to change your ChatGPT background
• Chrome extension permissions explained