ChatGPT models in 2025: GPT-4o, GPT-4.1, o3, o4-mini, GPT-5, and what changed in 2026
Updated: 4 days ago
This page preserves the 2025 ChatGPT model lineup as a historical snapshot and explains what happened to those models during the 2026 transition.
The 2025 picker included GPT-4o, GPT-4.1 variants, o-series reasoning models, and the first GPT-5 generation. Most of that lineup is no longer part of the current standard ChatGPT experience.
··········
WHY THE 2025 MODEL LINEUP LOOKED SO DIFFERENT
ChatGPT still presented multiple named model families side by side in 2025. General-purpose GPT models and o-series reasoning models were easier to interpret as separate products than today's combination of base-model families and reasoning controls.
........
2025 model | 2025 role | 2026 status in ChatGPT |
|---|---|---|
GPT-4o | General multimodal flagship | Retired from ChatGPT on February 13, 2026 |
GPT-4.1 / 4.1 mini | Coding and efficient general work | Retired from ChatGPT on February 13, 2026 |
o4-mini | Efficient reasoning | Retired from ChatGPT on February 13, 2026 |
o3 | Deeper reasoning | Retired from ChatGPT on August 26, 2026 |
GPT-5 Instant / Thinking | First GPT-5 ChatGPT split | Retired from ChatGPT in February 2026 |
GPT-5 Pro | Higher-end GPT-5 option | Transition access ended after February 19, 2026 |
........
··········
GPT-4O WAS THE GENERAL MULTIMODAL REFERENCE POINT
GPT-4o combined text, image, and conversational capabilities and remained an important ChatGPT reference model through 2025. OpenAI retired it from standard ChatGPT on February 13, 2026, while initially leaving API availability unchanged.
··········
GPT-4.1 AND GPT-4.1 MINI EMPHASIZED CODING AND EFFICIENCY
GPT-4.1 and its mini variant were widely used for coding, instruction-following, and API workflows. They also left ChatGPT on February 13, 2026, even though ChatGPT retirement did not automatically mean immediate API retirement.
··········
O3 AND O4-MINI REPRESENTED THE REASONING BRANCH
The o-series made reasoning a distinct model-selection decision. o4-mini left ChatGPT in February 2026, while o3 received a longer sunset and was retired from ChatGPT on August 26, 2026.
··········
GPT-5 INTRODUCED INSTANT, THINKING, AND PRO AS A NEW STRUCTURE
The first GPT-5 generation moved ChatGPT toward a layered experience where fast responses, deeper reasoning, and Pro work were surfaced separately. GPT-5 Instant and Thinking were retired in February 2026, followed by later GPT-5.x transitions.
··········
THE 2026 TRANSITION ACCELERATED THROUGH GPT-5.1 AND GPT-5.2
GPT-5.1 Instant, Thinking, and Pro were retired from ChatGPT on March 11. GPT-5.2 equivalents followed on June 12, with existing conversations moving to GPT-5.5 counterparts.
··········
WHAT REPLACED THE 2025 PICKER
By September 2026, the current experience centers on GPT-5.6 Luna for Free and Go, GPT-5.6 Sol for eligible paid users, GPT-5.6 Sol Pro for harder Pro-class tasks, and GPT-6 Pro above the GPT-5.6 family.
··········
HOW TO USE THIS PAGE TODAY
Treat the 2025 names as historical and migration references. For a current model decision, use a current-lineup page; for API compatibility, verify the API's own model catalog because ChatGPT and API retirements do not always happen at the same time.
··········
FOLLOW US FOR MORE
··········
DATA STUDIOS
··········
