A fast and lightweight Tampermonkey userscript that:
✅ Automatically enables Temporary Chat mode
✅ Automatically selects GPT-4o
✅ Adds a Ctrl + Space keyboard shortcut to toggle Temporary Chat
✅ Skips execution entirely if URL already has ?model=gpt-4o&temporary-chat=true
✅ Optimized for speed and reliability — even on route changes
- 🧠 Auto-enables Temporary Chat on every page load
- ⚡ Forces GPT-4o model selection after temp chat
- 🎛️ Ctrl + Space toggle to manually switch temp chat on/off
- 🧪 Smart checks to avoid redundant actions
- 🔁 Detects route changes and reapplies settings if needed
- 🛑 Does not run if URL already includes the correct query params
📝 Important Notes If you're not seeing GPT-4o in the model selector: 1- Go to chatgpt.com on a PC or browser 2- Open Settings → General 3- Enable "Show legacy models" ❌ This script does not work in the ChatGPT mobile app
- Install Tampermonkey for your browser.
- Click “Create a new script” in the Tampermonkey dashboard.
- Paste in the contents of chatgpt-gpt4o-automation.js.
- Save the script and reload https://chatgpt.com.
| Key Combo | Action |
|---|---|
Ctrl + Space |
Toggle Temporary Chat manually |
- Uses fast polling (
15ms) for near-instant detection - Mimics real mouse and keyboard events for compatibility
- Uses mutation-safe selectors and retry strategies
- Runs in strict order: Temp Chat → GPT-4o
OpenAI no longer allows selecting models or toggling Temporary Chat via URL parameters alone. For example, visiting: https://chatgpt.com/?model=gpt-4o won’t apply the desired settings automatically.
This script solves that by simulating real user interaction to:
- ✅ Enable Temporary Chat
- ✅ Select GPT-4o via the dropdown
🛑 If the URL contains model=gpt-5, the script respects your choice and will not force GPT-4o. Additionally, if model=gpt-4o&temporary-chat=true is already set, the script won’t run at all to avoid unnecessary processing.
Maintained by MHSEA
Pin this script to the top of your Tampermonkey list to ensure it runs before others!