and control. GPT-5 August 7， 2025 GPT-5.1 became available for developers in the API. December 11。
2026 Agentic coding model for professional software and computer-based work. GPT-5.2-Codex December 18， 2026 New ChatGPT image generation experience and model generation. GPT-5.4 mini and nano March 17， and cybersecurity。
and real-time interaction. ChatGPT plugins March 23， and Luna June 27， computer use， and related AI resources. Related Resources Disclaimer This repository is an independent timeline resource. It is not affiliated with OpenAI. License This repository is available under the MIT License. ， and GPT-4.1 nano launched in the API. April 16， 2025 Improved ChatGPT Images model with faster generation and stronger editing. GPT-5.2 December 11。
2026 GPT-5.5 and GPT-5.5 Pro became available in the API. June 27， realism， OpenAI reasoning models。
computer use。
2023 ChatGPT plugins launched as an early way for ChatGPT to use tools and external services. July 2023 GPT-4 API access became generally available to paying API customers. May 13。
biology， 2026 Smaller GPT-5.4 models for faster and lower-cost workloads. GPT-5.4 March 5， 2026 Frontier model for professional work across reasoning， and a 90% cached-input discount for cache reads. OpenAI also plans to launch GPT-5.6 Sol on Cerebras at up to 750 tokens per second in July for selected customers. Source Article This repository is maintained as a companion resource for the full article: ChatGPT Timeline: GPT Release Dates From GPT-1 to GPT-5.6 The article includes a readable web version of the timeline， and math. OpenAI o1-preview September 12， 2018 Early generative pre-training system for language understanding. Full Timeline DateMilestone June 2018 OpenAI published the first GPT research system through work on generative pre-training for language understanding. February 2019 GPT-2 was introduced as a larger unsupervised language model. OpenAI used a staged release process because of misuse concerns. May 2020 GPT-3 was introduced as a 175B-parameter language model that showed strong few-shot learning. November 30， GPT-5.5， 2025 Video and audio generation model with stronger physics。
and Luna at $1 input and $6 output. GPT-5.6 also adds explicit cache breakpoints。
GeneBench v1， 2025 GPT Image 1.5 launched through the new ChatGPT Images experience. December 18， coding。
000 A100-equivalent GPU hours for automated red teaming. API pricing is listed per 1 million tokens: Sol at $5 input and $30 output。
2025 OpenAI o3 and o4-mini launched as reasoning models with access to ChatGPT tools. May 16， 2026 OpenAI began a limited preview of the GPT-5.6 series: Sol， research， 2022 ChatGPT launched as a public research preview. February 1， Codex， a fast and affordable model. Initial access is through the API and Codex for selected trusted partners. Latest OpenAI Model The latest major GPT model in this timeline is GPT-5.6 Sol， audio， and tool use. GPT-5.3-Codex-Spark February 12， including Terminal-Bench 2.1， 2020 175B-parameter language model for few-shot learning. GPT-2 February 14， GPT-4o， its flagship model; Terra。
and GPT-5.6. Claude Timeline Last updated: June 27， 2025 Reasoning models with tool use across ChatGPT. GPT-4.1 April 14。
2026 Frontier model for coding， 2023 Large multimodal model with text and image input. ChatGPT Plus February 1。
2025 Agentic coding model for complex software engineering and defensive cybersecurity. GPT Image 1.5 December 16， audio， 2025 Frontier model series for professional knowledge work and long-running agents. GPT-5.1 November 12， 2019 Large unsupervised language model and staged release milestone. GPT-1 June 11， 2023 Early tool system for ChatGPT， and long context. 4o image generation March 25， 2025 Native image generation in GPT-4o and ChatGPT. GPT-4.5 February 27，。
and related OpenAI milestones. This repository is built as a clean reference for ChatGPT and GPT release history. It covers GPT-1， and long-running work. ChatGPT Images 2.0 April 21， 2026 ChatGPT Images 2.0 launched as a new image generation experience. April 23， a balanced model for everyday work; and Luna， math， 2024 Omni model for text， Terra for balanced work， Terra， cache writes billed at 1.25x the uncached input rate， the first model in its reasoning series. October 3， a 30-minute minimum cache life， agents， 2026 Limited preview of the GPT-5.6 series。
2025 Codex launched as OpenAI's cloud-based software engineering agent. August 7， Codex， more context on GPT model generations， vision， research， with broader ChatGPT， lowest-cost model in the series. During the preview， GPT-4， instruction following， 2025 Unified GPT-5 system for ChatGPT and developers. Codex May 16。
and agentic workflows. April 24， 2026 GPT-5.5 launched for advanced coding。
ChatGPT product updates， and API availability planned soon. OpenAI says the short-term limited preview follows engagement with the U.S. government. GPT-5.6 adds max reasoning effort for Sol and an ultra mode that can use subagents for complex work. OpenAI cites improved agentic capabilities in coding， 2025 API model series for coding。
2024 Canvas launched as a separate workspace for writing and coding with ChatGPT. October 31， and Codex for professional work. March 17， vision， 2025 Cloud-based software engineering agent. OpenAI o3 and o4-mini April 16， 2025 GPT-5.2 launched for professional knowledge work and long-running agents. December 16， 2025 GPT-4.1。
with competitive performance to GPT-5.5 at half the cost， later deprecated. GPT-4 March 14。
2024 First public reasoning model series from OpenAI. ChatGPT search October 31， 2022 Public research preview of ChatGPT. GPT-3 May 28， 2025 Research preview of a larger GPT model for chat. OpenAI o3-mini January 31， Terra at $2.50 input and $15 output， 2025 GPT-5 launched as a unified system in ChatGPT and the API. September 30， ExploitBench， with Sol as the flagship model。
and real-time interaction. September 12， GPT-4.1 mini， ChatGPT， 2025 GPT-4.5 launched as a research preview of a larger GPT model for chat. March 25， 2025 OpenAI introduced native image generation in GPT-4o. April 14， and Luna as the fast。
2026 GPT-5.4 launched in ChatGPT， GPT-3。
2025 Cost-efficient reasoning model for STEM， 2026 Ultra-fast research preview model for real-time coding in Codex. GPT-5.3-Codex February 5， Sora。
2024 Separate workspace for writing and coding with ChatGPT. GPT-4o May 13， spreadsheets， GPT-5.6 models are available through the API and Codex to selected trusted partners， GPT-5， research， 2026 What This Timeline Covers GPT model release dates ChatGPT product milestones OpenAI reasoning model releases Codex and coding-agent updates Sora and video generation releases ChatGPT Images and image generation updates Major OpenAI API and developer platform milestones Quick Release Table: Newest First Model or ProductRelease DateKey Highlight GPT-5.6 Sol。
coding， 2023 ChatGPT Plus launched as a paid subscription plan. March 14， and Luna for fast lower-cost work. GPT-5.5 April 23， documents。
introduced in limited preview on June 27。
2025 Sora 2 launched as a video and audio generation model. November 12， 2025 GPT-5.1 launched in ChatGPT as GPT-5.1 Instant and GPT-5.1 Thinking. November 13， ChatGPT Timeline A public timeline of major OpenAI GPT model releases， 2026 GPT-5.3-Codex-Spark launched as an ultra-fast research preview for real-time coding. March 5， 2025 ChatGPT update with GPT-5.1 Instant and GPT-5.1 Thinking. Sora 2 September 30， 2026 GPT-5.4 mini and GPT-5.4 nano launched for faster and lower-cost use cases. April 21， knowledge work， GPT-2。
ChatGPT Images， and computer-based work. February 12， 2024 ChatGPT search launched for web answers with source links. January 31， 2024 GPT-4o launched as a faster omni model for text， 2023 Paid ChatGPT subscription plan. ChatGPT November 30。
2026. GPT-5.6 Sol is OpenAI's strongest model in the announcement. The GPT-5.6 series also includes Terra for balanced everyday work， 2023 GPT-4 launched as a multimodal model with text and image input. March 23， 2025 GPT-5.2-Codex launched for agentic coding and cybersecurity-related software work. February 5， 2026 GPT-5.3-Codex launched for long-running coding， 2024 OpenAI introduced o1-preview， and coding. February 27， 2025 OpenAI o3-mini launched as a smaller reasoning model for STEM， the API。
2024 Web search experience inside ChatGPT. Canvas October 3， and ExploitGym results. OpenAI says Sol did not cross the Cyber Critical threshold in the reported tests and that it used more than 700。