Monday Jun 29
PRODUCTOpenAI

OpenAI Retires GPT-4.5

27JUN
END OF GPT-4GPT-4.5NOW GPT-5

The chatbot era's last GPT-4 model is gone. OpenAI pulled GPT-4.5 from ChatGPT after a 30-day sunset. Old chats move to GPT-5 automatically.

It happened quietly. GPT-4.5 left ChatGPT on June 27 after a month-long wind-down.

Regular users do nothing. Conversations shift to GPT-5, which is faster and cheaper per token. The API keeps GPT-4.5 alive, so developers are not cut off.

The o3 model retires next, on August 26. Model deprecation is now a standing cost, not a one-off event.

full brief & sources

⚡ Why this matters

  • Closes the GPT-4 chapter inside the product most people associate with AI.
  • Makes model deprecation a recurring planning task for any team pinned to a version.
  • Shows OpenAI tidying its lineup right as GPT-5.6 looms and the IPO nears.

🔍 What happened

  • June 27: GPT-4.5 retired from ChatGPT after a 30-day sunset.
  • Existing GPT-4.5 chats migrate to GPT-5 with no user action.
  • The OpenAI API still supports GPT-4.5 separately.
  • GPT-4.5 launched February 2026 as the last pre-GPT-5 frontier model.
  • OpenAI o3 is scheduled to retire August 26 after a 90-day sunset.

💬 Smart takes

  • OpenAI: GPT-5 beats GPT-4.5 on every benchmark that matters, faster and cheaper.
  • Skeptic: teams that tuned prompts to GPT-4.5's voice must now re-baseline against GPT-5.

🧭 Where this goes

  1. Likelymore frequent model sunsets become normal as labs ship faster.
  2. Likelyenterprises add deprecation windows to their AI procurement checklists.
  3. Possiblea third-party market grows for pinning or emulating retired model behavior.
  4. Wild Carda regulator one day requires minimum support windows for production AI models.

🥄 The Spoon Take

This is the boring story that bites later. The model that taught millions what a chatbot is just got switched off, and almost nobody noticed. If your product leans on one model's exact behavior, its retirement is your problem, not the lab's. Treat model lifecycle like any vendor dependency.

🤔 Pushback

For almost everyone this is a non-event, since GPT-5 is better on every axis and the migration is automatic.

·Yahoo Tech - GPT-4.5 retired·witho2 - Migration guide