When you see the announcement that Codex can be used with ChatGPT’s Free plan, it’s easy to think that everything from chat to coding automation is provided under the same conditions. However, when checking the scope of free usage, you need to consider what features, on what screen, and how you access and use them.
This article distinguishes between general Chat, Work·Codex, and API based on official documents confirmed on October 9, 2026. API (Application Programming Interface) is the interface through which programs send requests to a service. The way a person chats in an app and a program’s API call can differ from the billing inquiry path.
1. Model application scope differs even within the same app
OpenAI’s September 22 changelog describes GPT-6 Sol and Luna as being available for Work and Codex, distinguishing that they are not applicable to general Chat. Therefore, reading the announcement “new models can be used in Codex” as a change to the default model for general chat can lead to incorrect conclusions. Official Changelog
This distinction is also useful when reading feature announcements with dates. Instead of just checking the model name in the announcement, you should also read the target plan and usage screen. For example, you cannot assume that the same permissions apply to the web or all development tools based solely on an announcement about a desktop app.
Figure: Three paths to determine usage scope. Reconstructed based on official documents — Changelog, Pricing & Usage Guide.
2. What is the scope of Free’s Codex announcement?
The current pricing document states that Free is $0 per month and provides GPT-6 Luna at Standard speed on the desktop app, with a condition of sequential rollout. This announcement does not guarantee unlimited workload. Official Pricing Guide
The model document also explains that availability may vary depending on deployment status, login method, and client. GPT-6.1 Sol’s launch rollout does not include Free and Go. You must distinguish between seeing a name in the model list and being able to select it in your plan. Official Model Guide
If a model is not visible on the screen, first check the app you are using and your login method. If the document’s target and your environment are the same, but availability is unclear, it’s best not to plan your work assuming you can use features not currently visible.
3. Free tier and remaining usage are different pieces of information
According to official documents, Work and Codex share usage. Current limits can be checked on the usage dashboard, and if you are already using Codex CLI, you can see the remaining limit with /status. There is also a note not to calculate the number of operations included in a subscription using the API token unit price. How to Check Pricing & Limits
For example, a request to fix a short file and a request to read multiple documents and generate results have different scopes of work. Rather than counting every request as a single “one time” to estimate daily throughput, it’s more realistic to start with small tasks and check actual remaining usage. This is an operational method that can be applied instead of providing a fixed number of free operations.
The model document explains that increasing the inference level can help with complex tasks but increases time and token usage. It suggests starting with default settings and adjusting when deeper review is needed. Inference Settings Explanation
4. Reconfirm cost criteria when using API keys
When using Codex via an API key, API pricing applies. You cannot assume that API call costs are also free just because you have a free ChatGPT account. Model access rights for API key paths also follow the models that key can use. API Key Usage Guide
If you intend to connect a program, you should check these three things before execution:
- Whether the connection method you are currently using is ChatGPT login or an API key
- Whether the required models and features are provided with that connection method
- On which screen you can check usage and costs
This check is not a procedure that unconditionally recommends either free or paid. It is a process to align the task you intend to use with the path through which costs are calculated.
5. Steps to check free scope
First, distinguish between Chat, Work·Codex, and API. Next, read the guide appropriate for your plan, app, and login method, and check the actually selectable models. Finally, look at the remaining usage and billing conditions.
This article does not confirm a complete list of free features for general Chat or unlimited text conditions. It also does not provide unconfirmed storage capacity or fixed counts per tool. In particular, do not transfer the limitations of the Work·Codex document to the entire general Chat.
The key to determining free usage is to check the usage screen, access conditions, usage, and billing path together, rather than just a model name. Distinguishing these four can more clearly separate tasks that can be started with a free account from those that require checking separate costs.
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