At the end of 2022, OpenAI launched ChatGPT and opened up an easy-to-access interface to large language models (LLMs) for the first time. The uptake was stratospheric.
Since the explosive launch, ChatGPT hasn’t shown signs of slowing down in developing new features or maintaining worldwide user interest. As of September 2025, ChatGPT now has a reported 700 million weekly active users and hundreds of plugins.
The following is a timeline of all key events since the launch up to October 2025.
History Of ChatGPT: A Timeline Of Developments
June 16, 2016 – OpenAI published research on generative models, trained by collecting a vast amount of data in a specific domain, such as images, sentences, or sounds, and then teaching the model to generate similar data. (OpenAI)
Sept. 19, 2019 – OpenAI published research on fine-tuning the GPT-2 language model with human preferences and feedback. (OpenAI)
Jan. 27, 2022 – OpenAI published research on InstructGPT models, siblings of ChatGPT, that show improved instruction-following ability, reduced fabrication of facts, and decreased toxic output. (OpenAI)
Nov. 30, 2022 – OpenAI introduced ChatGPT using GPT-3.5 as a part of a free research preview. (OpenAI)
Screenshot from ChatGPT, Dec 2022Feb. 1, 2023 – OpenAI announced ChatGPT Plus, a premium subscription option for ChatGPT users offering less downtime and access to new features.
Screenshot from ChatGPT, February 2023Feb. 2, 2023 – ChatGPT reached 100 million users faster than TikTok, which made the milestone in nine months, and Instagram, which made it in two and a half years. (Reuters)
Feb. 7, 2023 – Microsoft announced ChatGPT-powered features were coming to Bing.
Feb. 22, 2023 – Microsoft released AI-powered Bing chat for preview on mobile.
March 1, 2023 – OpenAI introduced the ChatGPT API for developers to integrate ChatGPT functionality in their applications. Early adopters included Snapchat’s My AI, Quizlet Q-Chat, Instacart, and Shop by Shopify.
March 14, 2023 – OpenAI releases GPT-4 in ChatGPT and Bing, which promises better reliability, creativity, and problem-solving skills.
Screenshot from ChatGPT, March 2023March 14, 2023 – Anthropic launched Claude, its ChatGPT alternative.
March 20, 2023 – A major ChatGPT outage affects all users for several hours.
March 21, 2023 – Google launched Bard, its ChatGPT alternative. (Rebranded to Gemini in February 2024.)
March 23, 2023 – OpenAI began rolling out ChatGPT plugin support, including Browsing and Code Interpreter.
March 31, 2023 – Italy banned ChatGPT for collecting personal data and lacking age verification during registration for a system that can produce harmful content.
April 25, 2023 – OpenAI added new ChatGPT data controls that allow users to choose which conversations OpenAI includes in training data for future GPT models.
April 28, 2023 – The Italian Garante released a statement that OpenAI met its demands and that the ChatGPT service could resume in Italy.
April 29, 2023 – OpenAI released ChatGPT plugins, GPT-3.5 with browsing, and GPT-4 with browsing in ALPHA.
Screenshot from ChatGPT, April 2023May 12, 2023 – ChatGPT Plus users can now access over 200 ChatGPT plugins. (Open AI)
Screenshot from ChatGPT, May 2023May 16, 2023 – OpenAI CEO Sam Altman appears in a Senate subcommittee hearing on the Oversight of AI, where he discusses the need for AI regulation that doesn’t slow innovation.
May 18, 2023 – OpenAI launched the ChatGPT iOS app, allowing users to access GPT-3.5 for free. ChatGPT Plus users can switch between GPT-3.5 and GPT-4.
Screenshot from ChatGPT, May 2023May 23, 2023 – Microsoft announced that Bing would power ChatGPT web browsing.
Screenshot from ChatGPT, May 2023May 24, 2023 – Pew Research Center released data from a ChatGPT usage survey showing that only 59% of American adults know about ChatGPT, while only 14% have tried it.
May 25, 2023 – OpenAI, Inc. launched a program to award ten $100,000 grants to researchers to develop a democratic system for determining AI rules. (OpenAI)
July 3, 2023 – ChatGPT’s explosive growth shows a decline in traffic for the first time since launch. (Similarweb)
July 20, 2023 – OpenAI introduced custom instructions for ChatGPT, allowing users to personalize their interaction experience. (OpenAI)
Aug. 28, 2023 – OpenAI launched ChatGPT Enterprise, calling it “the most powerful version of ChatGPT yet.” Benefits included enterprise-level security and unlimited usage of GPT-4. (OpenAI)
Nov. 6, 2023 – OpenAI announced the arrival of custom GPTs, which enabled users to build their own custom GPT versions using specific skills, knowledge, etc. (OpenAI)
Jan. 10, 2024 – With the launch of the GPT Store, ChatGPT users could discover and use other people’s custom GPTs. On this day, OpenAI also introduced ChatGPT Team, a collaborative tool for the workspace. (OpenAI)
Jan. 25, 2024 – OpenAI released new embedding models: the text-embedding-3-small model, and a larger and more powerful text-embedding-3-large model. (OpenAI)
Feb. 8, 2024 – Google’s Bard rebranded to Gemini. (Google – Gemini release notes)
April 9, 2024 – OpenAI announced that it would discontinue ChatGPT plugins in favor of custom GPTs. (Open AI Community Forum)
May 13, 2024 – A big day for OpenAI, when the company introduced the GPT-4o model, offering enhanced intelligence and additional features for free users. (OpenAI)
July 25, 2024 – OpenAI launched SearchGPT, an AI-powered search prototype designed to answer user queries with direct answers. Update: Elements from this prototype were rolled into ChatGPT and made available to all regions on Feb. 5, 2025. (OpenAI)
Aug. 29, 2024 – ChatGPT reaches 200 million weekly active users. (Reuters)
Sept. 12, 2024 – OpenAI unveiled the GPT o1 model, which it claims “can reason like a human.”
Oct. 31, 2024 – OpenAI announces ChatGPT Search. It became available to logged-in users starting Dec. 16, 2024, and on Feb. 5, 2025, it was rolled out to be available for all ChatGPT users wherever ChatGPT is available. (OpenAI)
Screenshot from ChatGPT, September 2025Jan. 31, 2025 – OpenAI releases o3-mini (smaller reasoning model; first in the o3 family). (Open AI)
April 16, 2025 – OpenAI introduces o3 and o4-mini (fast, cost-efficient reasoning; strong AIME performance). (OpenAI)
June 10, 2025 – o3-pro is made available to Pro users in both ChatGPT and API. (OpenAI)
Aug. 4, 2025 – ChatGPT approached 700 million weekly active users.
Screenshot from Nick Turley, VP and head of the ChatGPT app, X (Twitter) post, September 2025Sept. 15, 2025 – A New OpenAI study reveals that it reached 700 million weekly active users and how they use ChatGPT. (OpenAI)
Last update: October 01, 2025
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Featured image: Tada Images/Shutterstock
