This article contains PR (advertising) content. Prices and terms were confirmed with each company’s official information on October 10, 2026.
Comparing AI tools that run in a terminal, talk about monthly flat-rate plans and API pay-as-you-go easily gets mixed together. Claude Code, Codex, and Gemini CLI each hide a different system under the same word “monthly.”
Conclusion: the flat-rate plan is the entry point; pay-as-you-go starts after you overflow it
The conclusion is that all three officially offer both “what’s included in the flat-rate plan” and “API-key pay-as-you-go” — that much is common across them. What differs is what happens once you go past the flat-rate plan’s range.
| Claude Code | Codex | Gemini CLI | |
|---|---|---|---|
| Included in a flat-rate plan? | Included in the Pro and Max plans | Included in every plan from Free to Enterprise | Usable by logging in with a personal Google account |
| What happens when you overflow it | Keep going by enabling API credit | Shares usage with ChatGPT Work | Switching to a Gemini API key makes it pay-as-you-go |
| Where it runs | Terminal, IDE extension, desktop app, browser | Mainly the terminal | Terminal (npm, Homebrew, etc.) |
Looking first at what the flat-rate plan covers, then checking what happens once you overflow it, is the shortcut to choosing a terminal AI tool.
Flat-rate plan or API pay-as-you-go: all three wear both hats
On flat-rate vs. API pay-as-you-go, all three officially offer both “the basic way of using it, included in the flat-rate plan” and “pay-as-you-go with an API key.” What differs is the price of the flat-rate entry point.
Claude Code is included in Claude’s Pro plan ($20 USD/month) or in the Max plan (starting from the $100 USD/month tier).
Codex is included in every ChatGPT plan, including the free plan, and can also be used on Go ($8 USD/month) or Plus ($20 USD/month).
Gemini CLI can be used with no additional payment just by logging in with a personal Google account.
The chart below lines up the dollar-based plan prices for comparison.
Monthly price comparison in USD
Here’s the catch: all three line up at their entry price, but the price alone doesn’t tell you how much you can actually use. What happens once you overflow it is covered in the next section.
In short, if you just want to keep the monthly cost down, ChatGPT Go ($8 USD/month) is a candidate. If you want to pick by similar price point, Claude Pro or ChatGPT Plus (both $20 USD/month) are candidates.
Source: Claude’s official pricing page, ChatGPT’s official docs (confirmed October 10, 2026)
Usage limits: compare by “what happens when you overflow,” not the numbers
None of the three publish specific numeric usage limits for the general public. What you can compare is what happens after you hit the limit.
Using Claude Code on the Pro or Max plan comes with a per-session time limit and a weekly usage limit. After hitting the limit, you can keep going by switching to API-rate credit usage.
Codex shares usage with ChatGPT Work. This particular official doc page doesn’t state specifically how the overflow is handled.
Gemini CLI has two ways of using it: logging in with a personal Google account, and using a Gemini API key. Using an API key makes it pay-as-you-go.
Here’s the catch: even where it says “there is a limit,” the specific counts or time are only given in English-language figures. The only way to find the actual breaking point is to use it and feel where it overflows.
In short, it’s more realistic to choose based on whether it stops or switches to billing after you overflow, rather than on the exact numeric limit.
Source: Claude’s official help docs, ChatGPT’s official docs, Gemini CLI’s official repository (confirmed October 10, 2026)
Where it runs: not just the terminal
Claude Code supports the widest range of places to run — terminal, IDE extensions, desktop app, and browser. Codex and Gemini CLI are mainly used in the terminal.
Claude Code works in the terminal as well as in VS Code and JetBrains extensions, a desktop app, and a browser version.
Codex is built to explore code, plan changes, edit files, and run local dev tools, all inside the terminal.
Gemini CLI is installed via npm, Homebrew, MacPorts, or Anaconda, and used from the terminal.
The chart below summarizes what each is officially said to do.
What each one is officially said to do
Claude Code
Runs in the terminal, IDE extensions, desktop app, and browser
Codex
Included in every ChatGPT plan; explores, edits, and runs code in the terminal
Gemini CLI
Usable at no extra cost once you log in with a Google account
In short, if you want to keep working from outside the editor or from other screens, Claude Code fits; if you want to stay focused in the terminal, Codex or Gemini CLI fits.
Source: Claude’s official docs, Gemini CLI’s official repository (confirmed October 10, 2026)
Numbers measured on this Mac
What we measured is the time from running --version (showing the version) to getting a response back — not everyday startup time or answer speed.
| Tool | Version | Median | Disk needed to install |
|---|---|---|---|
| Claude Code | 2.1.283 | 0.008s | 0.45GB |
| Codex | 0.162.0 | 0.009s | 0.25GB |
| Gemini CLI | 0.60.0 | 0.766s | 0.10GB |
Codex only counts a single binary file, while the other two count an entire folder, so this isn’t an apples-to-apples comparison.
The measurement was taken on a Mac with an M4 Pro chip and 64GB of memory, running each tool 6 times on October 10, 2026, and using the median of runs 2 through 6. Here, 1GB means one billion bytes.
Gemini CLI took about 0.8 seconds just to display its version. This number is only a guide for the version-check moment, not a measure of actual working speed.
Recommendations by use case: which one to pick
If you want to try it for free first, Gemini CLI, which you log into with a personal Google account, is the lightest entry point. If you’re fine committing to a monthly payment, starting with Claude Pro or ChatGPT Plus is the simplest path.
If you already pay for ChatGPT at work, you can use Codex too at no extra cost. On the other hand, if you want to keep working from places other than the terminal, Claude Code supports more places.
What we could not confirm
Because this article relies only on official pages, the following points could not be confirmed this time.
- The specific per-session or per-day usage count or time limits for Claude Code, Codex, and Gemini CLI (not stated here because the source figures are in English-language units that can’t be cross-checked with this article’s verification method)
- How far Codex can be used on ChatGPT’s free plan, and the specifics of ChatGPT Work’s usage limit
- Whether Gemini CLI automatically switches to API-key billing once the free quota runs out, or simply stops working
- The actual code-generation speed or accuracy of the three tools (this article covers only pricing and terms of use)
Sources (all official, confirmed October 10, 2026)
The following official pages were checked directly on October 10, 2026.
- https://claude.com/pricing
- https://code.claude.com/docs/en/overview
- https://github.com/google-gemini/gemini-cli
- https://learn.chatgpt.com/docs/pricing
- https://learn.chatgpt.com/docs/codex/cli
- https://support.claude.com/en/articles/11145838-use-claude-code-with-your-pro-or-max-plan
Changelog
The table below lists the history of changes to this article.
| Date | Content |
|---|---|
| 2026-10-10 | First published |