OpenAI Codex CLI vs Gemini CLI: pricing, features and which to choose

OpenAI Codex CLI is a terminal coding agent maintained by OpenAI. The current project launched in 2025, and its client is licensed under Apache 2.0. It runs on macOS, Linux, and Windows, with authentication through ChatGPT, an API key, or an access token. Codex is also available through OpenAI’s web, IDE, desktop, and mobile experiences, but the CLI is the direct option for developers who prefer a shell. OpenAI does not publish a separate Codex CLI user count, revenue figure, or valuation. The project is active, with installation and release paths documented through npm, Homebrew, OpenAI documentation, and GitHub. The software is open source, while hosted models and account services remain proprietary. It is designed for developers seeking repository work and automation from a command line.

A normal Codex CLI session begins in a project directory with a request such as fixing a failing test or adding a feature. Codex inspects relevant files, proposes or applies changes, runs commands, and reports results. Workspace-write sandboxing, approval prompts, additional directories, JSON output, and unattended execution options provide different levels of control. The reference also documents image attachments, web search, slash commands, usage views, and multi-agent tools. Developers can use interactive sessions for exploration or non-interactive execution in scripts and CI. The app server and plugin paths extend the client to other interfaces. Command approvals remain important because repository edits, package operations, and tests can have side effects. These controls support both hands-on development and automation-oriented workflows.

Codex CLI suits developers who want terminal control, Apache 2.0 client code, and explicit boundaries around commands and files. It is less suitable for teams seeking a standalone CLI subscription, a fully local default model, or unrestricted unattended execution. Claude Code is the closest account-based alternative, while Gemini CLI provides a Google-centered terminal agent. Aider emphasizes a lightweight terminal workflow across model providers, and Cline offers an editor-centered approach. Codex’s API path also lacks cloud features such as GitHub code review and Slack integration. Choose Codex CLI when OpenAI models, ChatGPT billing, or an open client matter most, and retain approval prompts for unfamiliar repositories. Its audience is mainly terminal-focused developers, teams using sandbox controls, CI operators, and developers wanting an Apache 2.0 client.

Gemini CLI is Google's open source terminal agent for developers, students, researchers, and technical users who prefer a shell over a browser or IDE. Google launched it on June 25, 2025, connecting the client to Gemini Code Assist technology. The Apache License 2.0 covers the client, which supports coding, content generation, problem solving, research, and task management. A session begins with the gemini command and a prompt that can reference files in the working directory. The agent can read and edit files, run shell commands, fetch web content, and use Google Search grounding. Its repository reported more than 107,000 stars, 14,000 forks, and hundreds of contributors in October 2026. Google also reported millions of users in its May 2026 transition announcement.

Gemini CLI supports persistent project instructions through GEMINI.md files, while checkpointing and chat history help users resume work. Model Context Protocol support connects local or remote tools, and extensions add services including databases, BigQuery, Cloud Run, and security analysis. Headless mode accepts positional prompts and returns text, JSON, or streaming JSON for scripts and automation. Approval controls allow users to review commands and edits before execution. Gemini CLI launched with Gemini 2.5 Pro and a 1 million token context window. Google later added Gemini 2.5 Flash Lite, prompt completion, structured JSON output, improved editing, citations, database extensions, and broader MCP handling. In February 2026, Google announced Gemini 3.1 Pro preview support. The repository advertises Gemini 3 models and weekly stable and preview channels.

Claude Code is a direct alternative for developers committed to Anthropic models and its paid workflow. OpenAI Codex CLI fits teams already using Codex models or ChatGPT. Gemini CLI differs through Gemini models, Google Search grounding, MCP support, and Google Cloud integrations. It has no standalone subscription, although paid API and cloud routes require separate credential, quota, and billing administration. The client is Apache License 2.0 software, but that license does not cover Google's models or services. Choose Gemini CLI if you need Google's terminal tools, Search grounding, MCP, or Cloud integrations through an enterprise or paid API route. Choose Claude Code for Anthropic's workflow, or OpenAI Codex CLI for Codex and ChatGPT users. Gemini CLI is best for Google focused teams that want an inspectable terminal client.