Claude Code suits developers who want an agent that works across the terminal, IDEs, a desktop app and the web on a Claude Pro plan or above. Gemini CLI suits developers who want a fully open-source terminal agent and sign in with an API key or Vertex AI, because Google's own README says unpaid-tier and Google One users moved to Antigravity CLI. Check that note before you install Gemini CLI.
This comparison has changed under people's feet. I read Google's Gemini CLI repository and README on GitHub, and Anthropic's Claude Code docs and Claude plans page, so the facts below are current to those pages.
Gemini CLI and Claude Code compared
| Gemini CLI | Claude Code | |
|---|---|---|
| Free plan | Not named; unpaid tier moved to Antigravity CLI | Not on Claude Free; included from Claude Pro |
| Made by | Anthropic | |
| Open source | Yes, Apache 2.0 | Not stated on the pages I read |
| Where it runs | Your terminal | CLI, VS Code, JetBrains, desktop app, web |
| Sign-in options | Google sign-in, Gemini API key, Vertex AI | Claude plan or Anthropic Console; third-party providers in some surfaces |
| Latest models | README says it isn't optimised for Gemini 4 Argon | Claude models on your plan |
| Extending it | MCP servers, scripts | Plugins, Slack, CI, code review |
What Gemini CLI is now
Google's README describes Gemini CLI as an open-source AI agent that brings Gemini into your terminal, fully open source under Apache 2.0. It can query and edit large codebases, build apps from PDFs, images or sketches, connect MCP servers, and run in scripts for automation.
But two notes sit at the top of the README. It says unpaid-tier and Google One users had Gemini CLI replaced by Antigravity CLI on June 18th, 2026, and that Gemini CLI hasn't been optimised for Gemini 4 Argon, pointing people to Antigravity instead. The README still lists sign-in with Google, a Gemini API key and Vertex AI as ways to use it.
What Claude Code is
Anthropic's docs describe Claude Code as an agentic coding tool that reads your codebase, edits files, runs commands and works with your development tools. It runs in the terminal, in VS Code and JetBrains, in a desktop app and in the browser, and connects to Slack, a Chrome extension, code review and your own CI.
The docs say most surfaces need a Claude plan or Anthropic Console account, and the terminal, VS Code and JetBrains versions also support third-party providers. Anthropic's plans page lists Claude Code from Pro upwards.
The Antigravity change
This is the insight that matters most. If you used Gemini CLI on Google's unpaid tier or through Google One, Google's own README says that route moved to Antigravity CLI on June 18th, 2026. So older Gemini CLI vs Claude Code advice may not describe what you'll get today.
If you still want Gemini CLI itself, the README points to an API key or Vertex AI, which suit developers who want a specific model or enterprise controls. If you want Google's newest models in a terminal agent, the README sends you to Antigravity.
Release pace is another difference. The README says Gemini CLI publishes preview releases every Tuesday and promotes them to stable the following week, so expect frequent changes. Anthropic's docs point to a changelog for Claude Code, and its VS Code and JetBrains extensions let you stay inside your editor if the terminal isn't your favourite place to work.
Who each agent suits
Gemini CLI suits open-source fans and teams on Google Cloud who'll sign in through an API key or Vertex AI. Claude Code suits developers who want one agent across the terminal, editor and desktop, and teams already on Claude. My notes on what to look for in developer productivity tools help you judge either, and these prompts for faster coding work carry over well.
Want AI doing the heavy lifting in your marketing?
I build the systems that handle the boring 80 percent, so you get your week back. Done properly, with the human kept in.
My advice on Gemini CLI or Claude Code
Read the top of Google's README before you do anything else, because it tells you whether Gemini CLI or Antigravity CLI is the right Google tool for your account. Then run the same small task in each agent you can access, like adding a test to an existing function. Keep the one whose changes you'd approve without rewriting.
Do you make AI coding tools? Tool makers can ask to be considered for a featured place in comparisons like this one.
Frequently asked questions
Was Gemini CLI replaced by Antigravity?
Google's README says that for unpaid-tier and Google One users, Gemini CLI was replaced by Antigravity CLI on June 18th, 2026.
Is Gemini CLI open source?
Yes. Google's README says Gemini CLI is fully open source under the Apache 2.0 license.
Does Gemini CLI support Gemini 4 Argon?
Google's README says Gemini CLI hasn't been optimised for Gemini 4 Argon and points users to Antigravity.
Is Claude Code on the Claude Free plan?
No. Anthropic's plans page lists Claude Code from the Pro plan upwards.
Where does Claude Code run?
Anthropic's docs list the terminal, VS Code, JetBrains IDEs, a desktop app and the web.
