OpenAI announced on June 2 that Codex passed 5 million weekly users. The figure comes from OpenAI itself — self-reported, with no independent measurement behind it — but even discounted for that, the trajectory it describes is steep. Codex started 2026 at roughly 600,000 weekly users. Five months later it had added more than 4 million.
How fast is Codex actually growing?
Per OpenAI’s own milestones: roughly 600,000 weekly users at the start of 2026, 3 million around April 8, 4 million on April 21, and 5 million-plus announced June 2 — about a sixfold jump since the standalone desktop app launched in February. Sam Altman noted the 4 million mark arrived less than two weeks after 3 million. Every figure here is OpenAI self-reported.
We keep the running numbers — user milestones, release counts, model timeline — on our stats reference, updated as new figures land.
Who is driving the growth?
The growth is not coming from developers alone. The June 2 announcement — titled “Codex for knowledge work” — says about 20 percent of those 5 million-plus weekly users are knowledge workers rather than developers, and that this segment is growing three times faster than the developer base. That framing matches what we’re seeing elsewhere: OpenAI is positioning Codex as a general work agent, not only a coding tool, and the docs and desktop app have been folding toward ChatGPT branding at the same time.
What do the milestones mean for your usage limits?
Each one is a limit reset. Altman has publicly pledged a usage-limit reset at every additional million weekly users up to 10 million. With the count at 5 million-plus as of June 2, that leaves five more resets on the table — a recurring, roughly-predictable event for anyone budgeting Codex usage on a Plus or Pro plan. Given the pace so far (three separate million-user milestones between early April and early June), the next one may not be far off; that’s a projection on our part, not an OpenAI statement.
We track current per-plan limits, the credit system, and reset events on our living limits reference.
The caveat that stays attached
All of these numbers trace back to one source: OpenAI’s own announcements. No third party independently measures Codex weekly users, so treat the curve as directionally credible and precisely unverifiable. When OpenAI publishes the 6 million milestone — and the reset that comes with it — we’ll cover it here and update the stats page the same day.