Skip to main content
  1. ChatGPT Timeline Hub: Releases, Features, and Major Events/

ChatGPT Model Release Timeline: Year-by-Year Tracking of Iterations, Capability Leaps, and Rollout Cadence

Table of Contents

sources: OpenAI API Changelog / OpenAI News

2026
#

DateModel/ProductCore features and breakthroughs
2026-04-23GPT-5.5 / GPT-5.5 ProOpenAI introduced GPT-5.5 as its smartest and most intuitive model, rolling out in ChatGPT/Codex for Plus/Pro/Business/Enterprise tiers, with GPT-5.5 Pro for Pro/Business/Enterprise. Source: Introducing GPT-5.5
2026-04-21ChatGPT Images 2.0OpenAI released ChatGPT Images 2.0 and framed it as “a new era of image generation.”
2026-03 (rollout)GPT-5.4 Thinking (ChatGPT)ChatGPT began rolling out GPT-5.4 Thinking (using the “Thinking” naming on ChatGPT); targeted at reasoning, coding, and agentic tasks. Note: ChatGPT naming and rollout cadence may not fully match API model names.
2026-03 (rollout)GPT-5.4 mini (ChatGPT)Rolled out gradually in ChatGPT; used as a fallback in some plans/scenarios when GPT-5.4 Thinking hits rate limits.
2026-03-17gpt-5.4-mini / gpt-5.4-nanoReleased gpt-5.4-mini and gpt-5.4-nano (Chat Completions / Responses): mini targets high-concurrency, cost-efficient scenarios and supports tool search / computer use / compaction; nano targets simpler high-concurrency tasks, supports compaction only.
2026-03-05gpt-5.4 / gpt-5.4-proReleased gpt-5.4 (Chat Completions / Responses) and gpt-5.4-pro (Responses), adding tool search, built-in computer use, a (1M)-token context window, and native compaction for long conversations and agent workflows.
2026-03-03gpt-5.3-chat-latestReleased gpt-5.3-chat-latest (Chat Completions / Responses API), mapped to the latest GPT‑5.3 (Instant) snapshot currently used in ChatGPT.
2026-02-24gpt-5.3-codexReleased gpt-5.3-codex (Responses API).

2025
#

DateModel/ProductCore features and breakthroughs
2025-12-11GPT-5.2Released GPT-5.2 (Instant/Thinking/Pro), and updated the knowledge cutoff date (officially noted as Aug 2025).
2025-11-12GPT-5.1GPT-5 was updated to 5.1 Instant/Thinking, with stronger style control and personalization options.
2025-08-07GPT-5New flagship model rolled out gradually; paid users could choose GPT-5 or GPT-5 Thinking, and Pro/Team had Thinking Pro.
2025-06-10OpenAI o3-proLonger-thinking variant to improve reliability; released for Pro users in ChatGPT and also available via API.
2025-05-14GPT-4.1 / GPT-4.1 miniCoding-focused models entered ChatGPT; 4.1 mini replaced 4o mini.
2025-04-16OpenAI o3 / o4-miniReasoning model update: o3 for stronger reasoning, and o4-mini for better cost-performance and higher usage limits.
2025-02-27GPT-4.5 (research preview)More natural conversational experience, stronger instruction adherence, and lower hallucination rate.
2025-01-31o3-miniCost-efficient reasoning model optimized for coding, math, and science, with developer features such as structured outputs and tools.

2024
#

DateModel/ProductCore features and breakthroughs
2024-09-12o1-preview / o1-miniFirst release of the reasoning series, targeting more complex math/coding/science tasks.
2024-07-18GPT-4o miniLaunched as a more cost-efficient small model for ChatGPT and developer scenarios.
2024-05-13GPT-4o (Omni)Native multimodal flagship covering text/vision/audio, with low-latency real-time interaction.
2024-02-15Sora (first reveal)Initial official reveal of the text-to-video model (capable of generating videos up to about 1 minute).

2023
#

DateModel/ProductCore features and breakthroughs
2023-11-06GPT-4 TurboReleased at DevDay with a larger context window and newer knowledge cutoff.
2023-03-14GPT-4Released; first introduced image input support (with text output).

2022
#

DateModel/ProductCore features and breakthroughs
2022-11-30ChatGPT (GPT-3.5)Public research preview launch.

There are no articles to list here yet.