GPT-5 History: From GPT-1 to GPT-5 Timeline

GPT-5 is OpenAI's fifth-generation large language model, released in 2025, representing the most capable AI system the company has publicly deployed as of that…

OpenAI Releases GPT-1, Establishing the Pre-Train Fine-Tune Paradigm for NLP

In June 2018, OpenAI published 'Improving Language Understanding by Generative Pre-Training,' introducing GPT-1 with 117 million parameters trained on BookCorpus. The mo…

OpenAI Withholds GPT-2 Full Release Citing Misinformation Risk — A Landmark AI…

OpenAI released GPT-2 in February 2019 but withheld the full 1.5 billion-parameter model, citing concerns that it could be weaponised to generate synthetic news, spam, a…

GPT-3 Launches With 175 Billion Parameters, Redefining What Language Models Can…

Released in June 2020 through a limited beta API, GPT-3's 175 billion parameters dwarfed every existing language model by roughly two orders of magnitude. For the first…

OpenAI Releases Codex and DALL-E, Expanding GPT Beyond Text Into Code and Images

In January 2021, OpenAI unveiled DALL-E, a GPT-3-derived model capable of generating images from text prompts, demonstrating that the transformer architecture generalise…

ChatGPT Goes Live, Reaching 100 Million Users Faster Than Any Consumer Product…

On 30 November 2022, OpenAI released ChatGPT as a free research preview built on GPT-3.5, a fine-tuned variant incorporating Reinforcement Learning from Human Feedback (…

OpenAI Launches GPT-4, a Multimodal Model That Passes the Bar Exam in the Top 1…

On 14 March 2023, OpenAI released GPT-4 as the backbone of ChatGPT Plus (priced at $20/month, approximately ₹1,650 at launch-day exchange rates) and via API. GPT-4 accep…

Sam Altman Is Fired and Rehired Within Five Days, Exposing OpenAI's Governance…

On 17 November 2023, OpenAI's board abruptly dismissed CEO Sam Altman, citing a breakdown of trust over candour on safety matters. The move triggered a near-total employ…

OpenAI Launches GPT-4o, Bringing Real-Time Voice and Vision to Free-Tier ChatGP…

In May 2024, OpenAI unveiled GPT-4o ('o' for omni), a single model natively processing text, audio, and images in a unified architecture — rather than chaining separate…

India's ₹10,372 Crore AI Mission Approves Compute Access and LLM Development fo…

In March 2024, the Indian government approved the IndiaAI Mission with a ₹10,372 crore outlay over five years, citing GPT-class model capabilities as the competitive ben…

OpenAI's o1 and o3 Models Pioneer Chain-of-Thought Reasoning, Previewing GPT-5'…

Through 2024, OpenAI released the o1 and o3 model series — not branded as GPT but deeply informing GPT-5's development. These models spent compute at inference time 'thi…

OpenAI Releases GPT-5, Unifying Reasoning and Multimodal Capabilities in a Sing…

OpenAI released GPT-5 in May 2025, positioning it as a unified replacement for the fragmented GPT-4 family — consolidating GPT-4o's multimodal speed with the o-series' d…