Claude Code vs Codex vs Antigravity
One from each of the three big labs. They differ less in capability than in what their subscriptions let you do — and one of them is free.
Updated August 28, 2026 · Independent comparison — Claude Code, Codex CLI, Antigravity CLI are separate products.
Claude Code
Anthropic's first-party coding agent
Claude Code is Anthropic's first-party coding agent, running as a CLI, as IDE extensions and inside claude.ai. It is proprietary — the public repository is not OSI-licensed. It runs on a Claude Pro or Max subscription or a pay-as-you-go API key, and can be pointed at third-party labs by aiming ANTHROPIC_BASE_URL at a GLM, Qwen or Kimi coding-plan key. Its constraint is that on a subscription its quota is shared with claude.ai chat, and extra terminals do not get their own bucket.
Codex CLI
OpenAI's open-source coding CLI
Codex CLI is open source, though the cloud product around it is not. It runs across CLI, IDE, web, iOS and Codex Cloud, on GPT-5.6 and GPT-5.3-Codex, driven either by a ChatGPT plan or an API key. Its distinguishing feature is that a consumer ChatGPT subscription includes background and cloud compute rather than only local runs — Codex Cloud tasks draw on the same quota rather than being a separate SKU.
Antigravity CLI
Google's agent-first CLI and IDE
Antigravity CLI is Google's agent-first command line, shipping alongside the Antigravity IDE and free in public preview. It runs the Gemini family, with limited non-Gemini models on a separate and smaller quota because of capacity. There is no bring-your-own-key path — AI Studio keys are a different product. It is the successor path to Gemini CLI, whose free Gemini Code Assist serving is reported to have ended on 2026-06-18.
Bottom line
Claude Code, Codex CLI and Antigravity CLI are the three big-lab first-party coding agents, and the practical differences are structural rather than about editing quality. Claude Code is proprietary, included with Claude Pro or Max, and shares its quota with claude.ai chat — extra terminals drain the same pool. Codex CLI is genuinely open source (the cloud product around it is not), is included with any ChatGPT plan from Go upward, and uniquely includes background and cloud compute on a consumer subscription rather than as a separate SKU. Antigravity CLI is a proprietary preview, free today, Gemini-only with limited non-Gemini models on a smaller separate quota and no BYOK path at all; it is the successor to Gemini CLI, whose free serving is reported to have ended on 2026-06-18.
Status & licence
| Feature | Claude Code | Codex CLI | Antigravity CLI |
|---|---|---|---|
| Status | Active | Active | Public preview |
| Licence | Proprietary — the public repo is not OSI-licensed | Open source (the cloud product is proprietary) | Proprietary preview |
| Price | Included with Claude Pro ($20) or Max ($100/$200) | Included with ChatGPT Plus ($20) or Pro ($100/$200) | Free in public preview |
Where and how it runs
| Feature | Claude Code | Codex CLI | Antigravity CLI |
|---|---|---|---|
| Where it runs | CLI, IDE extensions, claude.ai | CLI, IDE, web, iOS, Codex Cloud | Antigravity CLI and IDE on Windows, macOS and Linux |
| Model support | Claude family; third-party labs via ANTHROPIC_BASE_URL | GPT-5.6 and GPT-5.3-Codex | Gemini family; limited non-Gemini on a separate quota |
| BYOK | Partial — Anthropic key, or an Anthropic-compatible coding-plan key | Yes, via the API-key path | ✗ |
| Subscription support | Claude Pro or Max | ChatGPT Go, Plus or Pro | Free in preview; Google AI plans raise the quota |
Capabilities
| Feature | Claude Code | Codex CLI | Antigravity CLI |
|---|---|---|---|
| Parallel sessions | Terminals share one subscription pool | Cloud tasks; the $200 tier is marketed for parallel projects | Multi-agent by design; the weekly cap is the throttle |
| MCP support | ✓ | ✓ | Not published |
Verdict at a glance
| Feature | Claude Code | Codex CLI | Antigravity CLI |
|---|---|---|---|
| Standout feature | The strongest agentic editing quality | Cloud and background compute on a consumer subscription | Editor, terminal and browser agents together, at no cost |
The Verdict
Choose Claude Code if...
- ✓You want the strongest agentic editing quality and Anthropic's models
- ✓You want IDE extensions as well as a CLI
- ✓You want to point the agent at GLM, Qwen or Kimi coding-plan keys
- ✓You already pay for Claude Pro or Max
Choose Codex CLI if...
- ✓You want an open-source harness you can inspect and fork
- ✓You want cloud and background tasks included on a consumer subscription
- ✓You want the widest surface coverage: CLI, IDE, web and iOS
- ✓You want a real BYOK path via an API key
Choose Antigravity CLI if...
- ✓Free matters and Gemini models do your work
- ✓You want editor, terminal and browser agents as one product
- ✓You are comfortable on a preview with an unpublished weekly quota
- ✓You are migrating off Gemini CLI and want the supported path
Frequently Asked Questions
What is the difference between Claude Code, Codex CLI and Antigravity CLI?
Claude Code is Anthropic's first-party coding agent, running as a CLI, as IDE extensions and inside claude.ai. Codex CLI is open source, though the cloud product around it is not. Antigravity CLI is Google's agent-first command line, shipping alongside the Antigravity IDE and free in public preview.
Which of Claude Code, Codex CLI and Antigravity CLI should I pick?
Choose Claude Code if you want the strongest agentic editing quality and Anthropic's models. Choose Codex CLI if you want an open-source harness you can inspect and fork. Choose Antigravity CLI if free matters and Gemini models do your work.
1DevToolRun them side by side instead of choosing
These agents are not mutually exclusive — they are processes, and most developers end up wanting two or three for different jobs. 1DevTool runs Claude Code, Codex CLI, Cline, OpenCode and Gemini CLI in persistent terminals in one window, each on its own subscription or key, plus an HTTP client, a 13-engine database client and an embedded browser. One-time $29, no subscription.