For a stretch this month, ChatGPT Plus subscribers using Codex and ChatGPT Work had no five-hour usage cap — OpenAI lifted it to celebrate crossing another million active users. As of 25 August, the cap is back.
The reason given is specific and, unusually for a usage-limit announcement, candid: it is about smoothing compute load, and about a real problem with how casual users were behaving without the cap in place.
What is changing, and for whom
The five-hour limit returns for Codex and ChatGPT Work on Plus subscriptions starting 25 August. Pro subscribers, at both the $100 and $200 tiers, remain exempt for the coming months — the celebratory removal effectively becomes a permanent Pro benefit rather than a temporary one for everyone.
Why OpenAI says it is doing this
Thibault Sottiaux, OpenAI's engineering lead, posted the reasoning directly on X rather than burying it in a help-centre note. Two claims, both worth taking at face value because they are specific rather than vague: the five-hour limit lets OpenAI smooth load on its compute while keeping the plan generous, and casual users were accidentally burning through their whole week's usage and then getting confused about why.
That second point is the more interesting admission. An uncapped tier does not just cost OpenAI more compute — it produces a worse experience for the exact users a five-hour window is meant to protect, because a burst of unplanned heavy use early in the week leaves nothing for the rest of it. Removing the cap to mark a milestone was a celebration; restoring it is presented as fixing a side effect nobody intended.
What happens when you hit the limit
Three options, none of them a hard stop: wait for the usage window to reset on the next cycle, buy additional credits, or draw on banked resets earned through promotions and referrals.
That third option is worth checking if you have one sitting unused — a banked reset from an old promotion is exactly the kind of thing that is easy to forget about until a cap you had stopped thinking about reappears.
The pattern this fits
This is the same shape of story that has run through Copilot's pricing changes all month: a usage ceiling that exists to protect predictable cost and predictable load, temporarily loosened for a promotional reason, then restored with a stated technical justification once the promotion ends.
The specific admission that casual users were hurting themselves without the cap is the detail worth remembering the next time any vendor removes a limit to celebrate something — a generous-looking change and a genuinely better user experience are not always the same change, and this is a case where the vendor said so itself.