OpenAI's Codex coding assistant crossed 90 million installations in a single week, a surge the company attributes to the rollout of GPT-5.5. The milestone marks one of the fastest adoption spikes for a developer tool in recent memory.
What GPT-5.5 brought to Codex
The latest model powers Codex's ability to generate, debug, and explain code across dozens of programming languages. Users who updated to the new version saw noticeably faster completions and more accurate context handling, according to OpenAI's internal metrics. The jump from roughly 30 million weekly installs before the update to 90 million afterward suggests developers are hungry for the improved performance.
Why the number matters
Ninety million installs in seven days means Codex is now one of the most widely used AI developer tools by raw count. The figure includes both free-tier users and paid subscribers, though OpenAI has not broken down the split. The rapid growth also puts pressure on competitors like GitHub Copilot and Amazon CodeWhisperer, which have been adding features to keep pace.
OpenAI has not announced a specific date for the next Codex update, but the company typically ships model improvements every few months. The current GPT-5.5-powered version will likely see a point release before the end of the quarter. Developers watching the install numbers will be waiting to see whether the surge holds or levels off as the novelty fades.
