Custom Themes for ChatGPT, Claude & Gemini - ChatTheme

Make ChatGPT, Claude & Gemini look like anything. Pick a theme or describe one and AI builds it. Free, and nothing breaks.

Make ChatGPT, Claude and Gemini look like anything. Pick a theme, or describe the look you want and AI builds it on your chat in seconds. Free, no sign-up for the built-in themes. Only the look changes: every chat feature keeps working. ChatTheme is a theme extension for chatgpt.com, claude.ai and gemini.google.com. Pick a theme once and it follows you to all three. DESCRIBE IT AND AI BUILDS IT Open Create and type what you want: "a cozy cabin at night", "soft pastel and rounded", "a 2005 flip phone", "make it darker". The theme appears live on your chat. Ask for changes ("bigger font", "less blue"), undo any step and keep the ones you like. Creating themes with AI needs a free account. READY-MADE THEMES Start from the gallery: phones, desktops, terminals, handheld consoles and calm reading themes. Hover to preview a theme on your own chat, click to keep it. A new Theme of the week shows up every Monday. CUSTOMIZE EVERYTHING Change the colors, the font in ChatGPT, Claude or Gemini (all fonts ship with the extension), corner radius, the background and effects. Most themes come in a light and a dark version and can follow your system, so they fit dark mode or light mode. HIDE WHAT YOU NEVER USE Ask ChatTheme to hide or move parts of the page, or click Pick and point at them: a sidebar link, a button, a banner. Customize your ChatGPT, Claude or Gemini sidebar without touching anything else. Every tweak can be undone in one click. NOTHING BREAKS • Your messages, the input box, the send button, menus and the sidebar keep working. Frames sit around the app, never on top of the controls. • If a site changes its layout, ChatTheme switches to a safe mode that keeps your colors and drops the frame. • Press Alt+Shift+T, or use the switch in the side panel, to turn it off instantly. • No remote code and no remote fonts. PRIVACY ChatTheme never reads, stores or sends your conversations. It only restyles the page, and only on ChatGPT, Claude and Gemini.