Change GitHub Theme Without Logging In

For some genius reason, Microsoft decided to lock GitHub’s theme selection behind an account, forcing you to stay logged in to change it. Making github less accessibility for users.

While I agree that dark mode as a default is a fine idea, GitHub's dark theme is not great—I experience eye fatigue quickly. Since many projects are hosted on Microsoft's GitHub, and I refuse to log in just to change my theme, I decided to find a solution myself.

I'm not alone—there's an active discussion on GitHub about this issue: 🔗 GitHub Community Discussion

🚀 The Solution

This Chrome extension forces GitHub into light mode by overwriting the default dark theme, bypassing the need to log in.

GitHub automatically resets data-color-mode to auto on every page load, so simply changing it manually doesn’t work. This extension continuously overrides it to ensure GitHub stays in light mode.

📌 Installation

I do not intend to publish this extension on the Chrome Web Store, but you can install it easily by following these steps:

1. Clone the repository or download the ZIP file and extract it.
2. Open Chrome and go to chrome://extensions/.
3. Enable Developer Mode (toggle in the top-right corner).
4. Click "Load unpacked" and select the src folder inside the repo.

📢 Important Notes:

• You must keep the local extension files—removing them will uninstall the extension.
• Developer Mode must stay enabled—disabling it will deactivate the extension.

⚖️ License

This project is licensed under the GNU Affero General Public License v3.0. Feel free to fork, modify, and even publish it to the Chrome Web Store if you’d like! 🚀

🛠 Acknowledgments

• Icon from Flaticon (licensed for free personal & commercial use with attribution).
• Inspiration for overwriting the theme came from GitHub user matheusqmello.
• Developed with assistance from ChatGPT.