Is OpenAI Codex Turning the Tables on Claude Code?

OpenAI Codex has reached a significant milestone—20 million weekly active users (WAU), as confirmed by Tibo, the head of Codex, on X this week. This number aligns with earlier internal data obtained by CNBC, which indicated that OpenAI’s AI programming and work agent products had already hit around 20 million WAU.

The growth trajectory of Codex is even more striking when compared to its rival, Claude Code. According to the latest data from tracking platform TickerTrends (as of August 10), Codex saw a 20.8% growth rate over the past four weeks—nearly four times Claude Code’s 5.2% growth during the same period. Just a few months ago, the tables were turned: from February to June 2026, Claude Code was leading the AI coding space with explosive growth, leaving Codex far behind.

Claude Code’s growth has since slowed down. TickerTrends data shows that its annualized revenue experienced fluctuations in July: it dipped to $143.5 billion on July 27 before rebounding to $151.2 billion by August 10. While revenue hasn’t declined, its once-blistering growth rate has dropped to single digits, a sign that it may have saturated the early adopter market of programmers.

Unlike Claude Code, Codex is expanding beyond just developers. OpenAI’s disclosures reveal that around 20% of Codex users are knowledge workers—including analysts, marketers, designers, and investors—with this segment growing three times faster than the developer base. This broader user reach is likely contributing to Codex’s recent surge in growth.

Sources

• Zimu Bang (via Sina Finance)
• CNBC
• TickerTrends
• The Information
• OpenAI Official Disclosures
• Anthropic Research Reports