The Great Migration: OpenAI Sets ‘Sunsetting’ Date for GPT-4 Series
Tech News, San Francisco,04 February, 2026: In a move that signals the end of an era for the AI industry, OpenAI has officially confirmed it will retire its flagship GPT-4o and o4-mini models on February 13, 2026. The sunsetting of these models marks a total pivot toward the newer, more powerful GPT-5.2 architecture, forcing millions of users to migrate to the next generation of generative intelligence.
GPT-4o, released in mid-2024, became a household name for its human-like voice capabilities and perceived “emotional intelligence.” However, internal memos suggest that maintaining the legacy infrastructure for the 4-series has become inefficient.
“GPT-5.2 represents a fundamental shift from a chatbot to a reasoning engine,” said an OpenAI spokesperson. “While GPT-4o was our most empathetic model, 5.2 provides the logic and multi-tool orchestration required for the autonomous agent era.”
Key Deadlines for Users
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February 13, 2026: The ChatGPT web and mobile interfaces will officially remove GPT-4o and o4-mini from the model selector.
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Automatic Migration: All active conversation threads currently using 4o will be automatically upgraded to GPT-5.2.
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API Grace Period: Enterprise developers using OpenAI’s API will be granted a 6-month extension to refactor their codebases before the legacy endpoints are permanently deactivated in August 2026.
What GPT-5.2 Brings to the Table
The mandatory shift isn’t without its perks. The GPT-5.2 architecture introduces several features that were previously impossible under the 4-series:
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The ‘Neural Coder’: A dedicated sub-module that can write, test, and deploy code in a sandboxed environment in real-time.
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Dynamic Personalization: To address complaints about the “sterile” feel of newer models, OpenAI is launching a “Style Slider” that allows users to mimic the conversational warmth of the retiring GPT-4o.
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Advanced Reasoning Tiers: Users can now toggle between “Instant” responses for simple tasks and “Pro Reasoning” for complex scientific and mathematical inquiries.
