OpenAI merges Codex with ChatGPT, targets 900M users ahead of IPO

OpenAI's merger of Codex and ChatGPT creates a super app targeting 900 million users, intensifying the AI race with Anthropic ahead of dueling IPOs.

OpenAI is merging its Codex coding agent with ChatGPT into a single desktop application, bringing Codex's superior task-execution capabilities to more than 900 million users as the company races Anthropic to go public.

"Codex is better than ChatGPT at handling long, multi-step tasks and calling external tools — that's why we're bringing them together," Thibault Sottiaux, OpenAI's head of core product and platform, said.

Codex reached 5 million weekly active users by the end of May, up from 3 million two weeks earlier, with enterprise revenue growing 50% week over week and overall usage rising about 5% daily, according to the company. The super app, which also integrates OpenAI's Atlas browser tool, will let users choose whether Codex or ChatGPT handles each query, with the system eventually routing tasks automatically between local and cloud execution.

The move comes as both OpenAI and Anthropic prepare for initial public offerings that could rank among the largest in history. Anthropic, which filed confidentially for an IPO on June 1, generates more than $47 billion in annualized revenue, with enterprise clients accounting for over 80% of that total. OpenAI, last disclosing $25 billion in annualized revenue in March, generates about 40% from enterprise and aims to reach 50% by year-end.

Codex's Rise From Developer Tool to Productivity Platform

Codex's rapid growth — from 3 million to 5 million weekly active users in roughly a month — reflects a strategic pivot OpenAI began in early 2025 after falling behind Anthropic on coding benchmarks. The company formed a dedicated team operating like a "startup within a startup," open-sourcing Codex's underlying code to accelerate feedback loops, Sottiaux said.

The technical gap that drove the merger is rooted in architecture. Codex runs on users' local devices with direct file access, while ChatGPT operates in the cloud. Codex also uses a superior "harness" — the software framework that lets AI agents call tools and execute actions on behalf of users, according to Sottiaux. The December 2024 release of GPT-5.2 improved Codex's ability to handle long-running tasks, and the April 2025 launch of GPT-5.5 — OpenAI's first new base model since GPT-4.5 in February 2025 — delivered a step-change in performance.

"GPT-5.5 made the gap impossible to ignore," Mitch Troyanovsky, co-founder of AI accounting startup Basis, said.

IPO Race Intensifies as Revenue Gap Narrows

The super app launch is designed to extend Codex's capabilities to OpenAI's vast consumer base, accelerating revenue growth ahead of a public listing. OpenAI also unveiled new Codex plugins for investment banking, sales and public equity analysis, with legal and corporate finance tools planned soon. The company emphasized it will not compete with partners like Canva and Figma, instead offering integrations — a contrast to Anthropic, which faced backlash for building competing design features.

Developers surveyed by The Information said Codex excels when given clear specifications, while Anthropic's Claude Code performs better when the problem is ill-defined and requires autonomous exploration. "When I have a clear spec, I trust Codex more to execute," Varun Rau, a software engineer at Notion, said.

For investors, the key question is whether OpenAI can close the revenue gap before its IPO. Anthropic's $47 billion in annualized revenue — up fivefold since the start of the year — gives it a commanding lead, but OpenAI's 900 million user base represents a massive untapped opportunity. OpenAI shares in private markets have been valued at $852 billion, while Anthropic's latest $65 billion fundraising round valued it at $900 billion.

This article is for informational purposes only and does not constitute investment advice.