OpenAI’s Codex Sees Over 60% Users Growth in 1 Week

OpenAI CEO Sam Altman revealed in a post on X that Codex is seeing rapid early adoption, crossing one million downloads in its first week.

“More than one million people downloaded the Codex App in the first week,” Altman wrote, adding that the platform recorded over “60% growth in overall Codex users last week”.

Altman also indicated that OpenAI plans to keep Codex accessible beyond its current promotional push. 

“We’ll keep Codex available to Free/Go users after this promotion. We may have to reduce limits there, but we want everyone to be able to try Codex and start building,” he said, signalling an emphasis on broad adoption even as usage scales.

The growth update comes just days after OpenAI announced GPT-5.3-Codex, its most advanced coding and agentic model to date. 

The new release expands Codex from a code-generation assistant into a system designed for long-running, autonomous work on computers, including research, debugging, deployment, and tool-driven workflows.

According to OpenAI, GPT-5.3-Codex combines the coding strengths of GPT-5.2-Codex with the broader reasoning and professional knowledge of GPT-5.2, while running roughly 25% faster. The company said the model achieves top performance on benchmarks such as SWE-Bench Pro and Terminal-Bench, with strong results on OSWorld and other agentic evaluations.

GPT-5.3-Codex is currently available to users on paid ChatGPT plans across Codex surfaces, including the web, app, CLI, and IDE integrations. OpenAI has said API access will follow after additional safety reviews.

OpenAI’s Codex is an AI-powered software engineering agent that understands natural language and translates it into functional code. It handles tasks such as writing, debugging, testing, refactoring, and coordinating work across a codebase. 

On February 2, OpenAI released the Codex app, marking a shift from browser- or CLI-based interactions to a focused native interface for agentic coding.

The Codex app is a dedicated standalone desktop application for macOS that acts as a “command centre” for managing and supervising multiple Codex agents running in parallel, automating workflows, and handling long-running development tasks without juggling terminals or multiple windows.