Firefox Browser Add-ons
Log in
Preview of GPThemes - ChatGPT Customization

GPThemes - ChatGPT Customization by itsmarta

Transform ChatGPT's user interface with customisable accent colours and font styles, modern designs and chat bubbles.

4.8 (11 reviews)4.8 (11 reviews)
297 Users297 Users
You'll need Firefox to use this extension
Download Firefox
Download file

Extension Metadata

Screenshots
GPThemes - New UI - DarkGPThemes - New UI - OLED + custom accent colorGPThemes - New UI - Light + custom accent colorGPThemes - Old UI - DarkGPThemes - Old UI - DarkGPThemes - Old UI - LightGPThemes - Old UI - Light
About this extension
🎨 WHAT AWAITS YOU 🎨
  • Custom/Full Chat & Prompt Field Width: Adjust the width of chat bubbles and prompt field to your preference, including full-width options for an immersive experience.
  • Custom Fonts: Personalize your ChatGPT interface with custom fonts, including font family, size, line height, and letter spacing.
  • Custom Accent Color: Personalize your chat experience with your chosen accent color, adding a unique touch to your conversations. See the live preview as you're selecting your perfect hue.
  • Modern themes: Light, Dark, and Black (AMOLED) for a stylish and more visually appealing experience.
  • Toggable Chat bubbles: Modern and sleek conversation design that clearly differentiate your messages from the AI's responses.
  • Effortless theme switching: Change themes on the fly with a single click using floating button. Well, fine, Mr. Nitpicker, technically it's a two-click saga 🥲.
  • Clean and spacious layout: No more feeling cramped, just generous spacing and clean lines for smooth chat sessions. Breathing unlocked.
  • Subtle animations: Enjoy a touch of elegance with subtle animations that enhance readability and flow.

🚀 DISCLAIMER 🚀

I'd like to remind you that ChatGPT frequently updates its website, and even minor changes can occasionally cause unexpected issues with the extension's functionality and appearance.

Your patience is greatly appreciated. If you notice any obvious issues with the appearance or functionality of the extension, please open an issue on the GitHub.
You can track the status on GitHub to stay informed.

Please note that this is a hobby project and it all depends on my available free time, but I'm working to resolve everything as soon as possible.
Thank you for your understanding.

🔒 PERMISSIONS 🔒
  • Storage: Saves your GPThemes preferences (font, accent colors, chat widths, etc.) for a consistent experience across all ChatGPT's URLs.
  • GPT Website Access: Enables GPThemes to customize the visual elements on chat.openai.com and chatgpt.com (new domain) for the optimal experience.

🚨 WARNING 🚨
  • Please be aware that GPThemes is currently tailored to enhance the experience for GPT-4o, GPT-4o mini, GPTs Store, DALL-E, Browsing and Data Analysis, Web Searching, Canvas, and Advanced Voice Mode, Create Image and new DeepSearch.
  • Premium/subscription models and My GPTs Editor are not fully supported! Probably the style is not as intended for certain elements!
    Exploring and editing all elements of those may be considered in future updates.

🕊️ FREE AND OPEN SOURCE 🕊️

GPThemes is not just an enhancement, it's a commitment to freedom. Embracing the spirit of open source, GPThemes is freely available for all users, ensuring an inclusive and accessible improvement to your ChatGPT experience.

🔗 https://github.com/itsmartashub/GPThemes

🤝 FEEDBACK AND SUPPORT 🤝

If you encounter persistent issues or have suggestions for improvement, please feel free to open an issue on GitHub or contact me via email. Your feedback is invaluable and helps me identify and resolve problems more effectively.

🔗 https://github.com/itsmartashub/GPThemes/issues
📫 gpthemes.contact@gmail.com
Rated 4.8 by 11 reviewers
Log in to rate this extension
There are no ratings yet

Star rating saved

5
9
4
2
3
0
2
0
1
0
Read all 11 reviews
Permissions and dataLearn more

Required permissions:

  • Access your data for chat.openai.com
  • Access your data for chatgpt.com
More information
Add-on Links
  • Homepage
  • Support site
  • Support Email
Version
5.2.1
Size
71.83 kB
Last updated
11 days ago (27 Jul 2025)
Related Categories
  • Appearance
Licence
GNU Lesser General Public Licence v3.0 only
Privacy Policy
Read the privacy policy for this add-on
Version History
  • See all versions
Tags
  • chat
  • dark mode
Add to collection
Report this add-on
More extensions by itsmarta
  • There are no ratings yet

  • There are no ratings yet

  • There are no ratings yet

  • There are no ratings yet

  • There are no ratings yet

  • There are no ratings yet

Go to Mozilla's homepage

Add-ons

  • About
  • Firefox Add-ons Blog
  • Extension Workshop
  • Developer Hub
  • Developer Policies
  • Community Blog
  • Forum
  • Report a bug
  • Review Guide

Browsers

  • Desktop
  • Mobile
  • Enterprise

Products

  • Browsers
  • VPN
  • Relay
  • Monitor
  • Pocket
  • Bluesky (@firefox.com)
  • Instagram (Firefox)
  • YouTube (firefoxchannel)
  • Privacy
  • Cookies
  • Legal

Except where otherwise noted, content on this site is licensed under the Creative Commons Attribution Share-Alike Licence v3.0 or any later version.