GPT Version Timeline: How AI Got Smarter Over the Years

The Generative Pre-trained Transformer (GPT) series has changed artificial intelligence from a research curiosity to a mainstream tool, empowering innumerable interactions daily. The realization about the evolution of GPT versions over the years reveals how each one launched breakthroughs in language understanding and practical applications across industries. GPT Version Comparison Table Features GPT-1 GPT-2 GPT-3 GPT-3.5 GPT-4 GPT-5 GPT-5.2 Release Date June 2018 Feb 2019 June 2020 Mar 2022 Mar 2023 Aug 2025 December 2025 Parameters 117M 1.5B 175B ~175B (optimized, fine-tuned) Estimated 1T (not disclosed, mixture-of-experts architecture) Estimated multi-trillion scale (MoE, highly efficient routing) Not publicly disclosed Training Data