ChatGPT Surpasses 400 Million Weekly Active Users, OpenAI Plans GPT-5 Launch

ChatGPT has crossed 400 million weekly active users (WAU), with over 2 million business users leveraging the tool for work, according to OpenAI COO Brad Lightcap.

“We feel very fortunate to serve 5% of the world every week,” Lightcap said in a recent post on X. He also noted a fivefold increase in reasoning model API usage since the launch of OpenAI’s o3 mini model. 

“2M+ business users now use Chatgpt at work, and reasoning model API use is up 5x since the o3 mini launch,” he said.

OpenAI is preparing to introduce GPT-4.5 and GPT-5 to ChatGPT and the API. Lightcap confirmed that free-tier users will have unlimited access to GPT-5, while Plus users will have the option to operate at “even higher intelligence.”

“GPT-5 will unify our GPT and o-series models into a single powerful model -- we think even low-taste testers will love it,” he added.

OpenAI also plans to expand ChatGPT’s agent capabilities this year, alongside other updates yet to be disclosed.

OpenAI’s growth comes as it faces new competition from China’s DeepSeek, which unsettled tech markets in January over concerns about its impact on U.S. AI companies’ profitability and dominance.

Meanwhile, OpenAI chief Sam Altman is considering whether OpenaI should open-source its next  AI project. Altman asked users on X whether they prefer an o3-mini-level model or a phone-sized version.

“For our next open-source project, would it be more useful to create an o3-mini-level model, which is relatively small but still requires GPUs, or the best phone-sized model we can develop?” Altman asked in a poll on X.

OpenAI is facing stiff competition from its competitors. xAI recently launched Grok-3 and made it freely available to all the users. Grok is currently the No. 1 app on the app store, surpassing ChatGPT and DeepSeek.  Independent benchmarks showed that Grok 3 outperformed Google Gemini 2 Pro, DeepSeek V3, Claude 3.5 Sonnet, and GPT-4 in tests such as AIME, GPQA, and LCB.

Meanwhile, Anthropic is preparing to launch its next reasoning model, a hybrid AI that will allocate more computational power to complex queries while efficiently handling simpler tasks.