What it is
ChatGPT is OpenAI's assistant. Codex is part of ChatGPT and comes as the ChatGPT desktop, mobile, and web apps, the Codex CLI, the Codex IDE extension, and Codex Cloud1. OpenAI's docs frame it around tasks such as exploring and understanding code, building a new feature, reviewing code, and fixing issues and failures1.
My plan
I have three ChatGPT Pro subscriptions, all on the $200-a-month tier, which comes to $600 a month at list price2. As of November 5, 2026, OpenAI says Pro comes in "$100, $200, or $500 USD per month" plans2. OpenAI's own pricing page describes the tiers as "Your choice of 3 usage tiers"3.
OpenAI's pricing page says Pro includes "Pro reasoning powered by GPT-6 Astra," longer Codex and ChatGPT Work sessions, unlimited and faster image creation, maximum deep research, and maximum memory and context3. Ultrafast mode is available on the $500 tier and eligible Enterprise and Edu plans2.
What it's good at
OpenAI labels Pro "Best for research and coding"3. Its Codex docs list code exploration, new features, code review, and fixing failures as the starting tasks1.
OpenAI's own limits show up as plan structure. Codex is included on Free, Go, Plus, Pro, Business, Edu, and Enterprise plans, so the Pro tiers buy more usage, not access2. OpenAI says faster modes use more of the included usage: Fast mode counts 2.5x, and the Ultrafast modes count 8x2. The Codex overview points to separate pages on permissions, sandboxing, and approvals rather than listing limits itself1.
What I use it for
Codex for software engineering, and ChatGPT for research.
The company
OpenAI was founded in December 2015 as the nonprofit OpenAI, Inc. Its founders include Elon Musk, Sam Altman, Ilya Sutskever, Greg Brockman, and Trevor Blackwell, and it is headquartered in San Francisco, California4.
Today it is a public benefit corporation, OpenAI Group PBC. The nonprofit OpenAI Foundation appoints all of its board members and can remove them at any time4. Microsoft is a major shareholder4. In 2026 OpenAI closed a funding round of $122 billion in committed capital at a post-money valuation of $852 billion4
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Sources
- ChatGPT | ChatGPT Learn (Overview). OpenAI, dated November 5, 2026.DocumentationRead
What it says: Codex surfaces: ChatGPT desktop, mobile, and web apps, the Codex CLI, the Codex IDE extension, and Codex Cloud. Starting tasks: explore and understand code, build a new feature, review code, fix issues and failures. Limits are linked to separate pages (permissions, sandboxing, approvals). Reached via redirect from developers.openai.com/codex.
- Pricing | ChatGPT Learn. OpenAI, dated November 5, 2026.DocumentationRead
What it says: Pro comes in "$100, $200, or $500 USD per month" plans. Codex is included on Free, Go, Plus, Pro, Business, Edu, and Enterprise. Fast mode counts 2.5x and the Ultrafast modes 8x against included usage; Ultrafast is on Pro $500 and eligible Enterprise/Edu plans. Reached via redirect from developers.openai.com/codex/pricing.
- Plans and Pricing | ChatGPT. OpenAI, checked November 5, 2026.Vendor pageRead
What it says: Pro is labeled "Best for research and coding" with "Your choice of 3 usage tiers." It lists Pro reasoning powered by GPT-6 Astra, longer Codex and ChatGPT Work sessions, unlimited and faster image creation, maximum deep research, and maximum memory and context. The fetched text omitted every dollar figure.
- OpenAI. Wikipedia, dated November 5, 2026.ArticleRead
What it says: Founded December 2015 as the nonprofit OpenAI, Inc.; founders include Elon Musk, Sam Altman, Ilya Sutskever, Greg Brockman, and Trevor Blackwell; headquartered in San Francisco. Now OpenAI Group PBC, with the OpenAI Foundation appointing all board members. Microsoft stake given as 23.3% (infobox) and 27% (text). A 2026 round of $122 billion at a post-money $852 billion, dated both March and April. Only the first 100,000 characters were read.