Changes

Changes that can move the estimates

Codex's plans, its models and this site's method all change. These are the changes that can shift what the plans page shows, newest first, each with the source it was checked against.

An estimate pools several recent weeks, so a change reaches it gradually: weeks from before and after it mix until the older ones age out. A change known only from second-hand reports stays off this list until its source can be read.

  1. · OpenAI

    GPT-5.5 retires from Codex

    Announced on September 14: GPT-5.5 leaves ChatGPT, ChatGPT Work and Codex on all plans. Weeks spent on it give way to weeks on other models, and each model draws on a limit at its own rate.

    Sources: OpenAI changelog, Sep 14, 2026, OpenAI pricing

  2. · OpenAI

    GPT-6.1 Sol reaches Codex and becomes the CLI's default

    OpenAI added GPT-6.1 Sol to Codex and ChatGPT Work, and Codex CLI 0.159.1 made it the default in its bundled model catalog. Sharers who keep the default move onto it, so weeks after this may hold a different number of tokens than weeks before.

    Source: OpenAI changelog, Sep 29, 2026

  3. · OpenAI

    GPT-6 Sol and GPT-6 Luna reach Codex

    Rolling out to Plus and Pro, among others, at lower token prices than the GPT-5.6 models before them. OpenAI's pricing page says credit prices alone do not set how fast a plan's included usage goes, so the effect on a weekly limit is not stated. Weeks on the new models may hold a different number of tokens than weeks before.

    Sources: OpenAI changelog, Sep 22, 2026, OpenAI pricing

  4. · OpenAI

    GPT-5.3-Codex-Spark is deprecated

    When its research preview opened to Pro on February 12, OpenAI said Spark's usage had limits of its own and did not count against the standard Codex limits. The plugin counts its tokens like any other, so a week with Spark in it can read high: more tokens than the weekly limit held. It is no longer available in the app, CLI or IDE extension.

    Sources: OpenAI changelog, Sep 14, 2026, OpenAI changelog, Feb 12, 2026

  5. · OpenAI

    GPT-5.4 and GPT-5.4 mini leave Codex for ChatGPT sign-in

    OpenAI named GPT-5.6 Terra and GPT-5.6 Luna as their replacements. The old models stay available with an API key, which is billed at API rates rather than drawing on a plan's limits.

    Sources: OpenAI changelog, Jul 31, 2026, OpenAI pricing

How the numbers work explains the estimate these changes act on.