Google Antigravity vs OpenAI Codex
Google Antigravity and OpenAI Codex side by side: plans and prices, models, where each runs, MCP and skills.
- Local servers
- Yes
- runs stdio servers
- Hosted servers
- Yes
- connects by URL
- Config
- TOML
- how servers are added
- Plugins
- Yes
- plugin marketplaces
Antigravity is Google's agent platform for building software. Codex is OpenAI's coding agent. Both have a free tier, a plan near $20 a month, a command-line version, an editor version and support for MCP and skills.
The big difference is the models. Codex's plans list OpenAI models. Antigravity offers Gemini models, and on Google AI Pro and Ultra also Claude models. Antigravity is on Google's plans (Google AI Pro is $19.99 a month as of November 2026), and Codex is on ChatGPT's plans (Plus is $20).
Good for
- Developers choosing a coding agent from Google or OpenAI
- Google AI Pro subscribers wondering if Antigravity replaces a ChatGPT plan
- ChatGPT subscribers curious about Antigravity
- People who want an agent in the terminal, the editor or a desktop app
Side by side
Our advice: use Antigravity if you want Gemini and Claude models in one tool on a Google AI plan. Use Codex if you already pay for ChatGPT or want an open-source CLI.
| Option | Google Antigravity | OpenAI Codex |
|---|---|---|
| Free plan | Yes, $0 | Yes, GPT-6 Luna in the desktop app (subject to rollout) |
| Plan near $20 | Google AI Pro, $19.99/mo | ChatGPT Plus, $20/mo |
| Higher plans | Google AI Ultra, $99.99 or $199.99/mo | ChatGPT Pro, $100, $200 or $500/mo |
| Models on the $20 plan | Gemini, Claude Sonnet and Opus 5.5, GPT-OSS-120b (GPT-OSS-120b is listed for removal on Nov 18, 2026) | GPT-6.1 Sol, GPT-6 Luna |
| Where it runs (Codex as listed on Plus) | App, CLI, IDE extensions, SDK | Web, CLI, IDE extension, iOS |
| MCP servers | Yes | Yes |
| Agent skills | Yes | Yes |
Which to pick
Our advice: pick Antigravity if you have Google AI Pro or Ultra and want Gemini and Claude models in one tool. Pick Codex if you pay for ChatGPT, or want a CLI whose source is open. Neither vendor publishes a head-to-head test, so try one real task in each.
The limit on each side: Antigravity's models depend on your Google AI plan, and Codex's pricing page lists only OpenAI models.
Best for
- Antigravity: Google AI Pro or Ultra subscribers who want the agent included
- Antigravity: people who want to switch between Gemini and Claude models
- Antigravity: anyone who wants a free start before paying
- Codex: ChatGPT Plus, Pro or Business subscribers
- Codex: developers who want to read or change the CLI source
Skip it if
- Antigravity: you want Claude Opus 5.5 or Sonnet 5.5 on a free plan, since Google lists them for paid Google AI Pro and Ultra
- Codex: you want Gemini or Claude models inside the agent, since its pricing page lists OpenAI models (GPT-6.1 Sol, GPT-6 Luna)
Questions
Is Antigravity better than Codex?
Neither wins outright. Neither vendor publishes a head-to-head test, and the answer depends on your code and the model you pick. Both have a free tier, so run the same task in each.
Is Google Antigravity free?
Yes, there is a $0 plan with a variety of agent models, unlimited Tab completions and basic weekly rate limits. Google AI Pro and Ultra add higher limits and more models (as of November 2026).
Is Codex free?
Partly. OpenAI's pricing page lists GPT-6 Luna in the desktop app for ChatGPT Free and Go, subject to rollout. It lists Codex on the web, in the CLI, in the IDE extension and on iOS under Plus at $20 a month (as of November 2026).
How much do Antigravity and Codex cost?
Antigravity is included with Google AI Pro at $19.99 a month and Google AI Ultra at $99.99 or $199.99. Codex is included with ChatGPT Plus at $20 and Pro at $100, $200 or $500 (as of November 2026).
Which models does each use?
Antigravity offers Gemini models and, on Google AI Pro and Ultra, Claude Sonnet 5.5 and Opus 5.5. It also lists GPT-OSS-120b, due for removal on November 18, 2026. Codex's pricing page lists GPT-6.1 Sol and GPT-6 Luna on Plus.
Can Antigravity use Claude models?
Yes. Google lists Claude Sonnet 5.5 and Opus 5.5 (thinking) on Google AI Pro for non-trial subscriptions, and on Ultra. Claude 4.6 models are listed on Free and Pro and are due to be removed on November 18, 2026.
Do both support MCP?
Yes. Antigravity supports MCP across its products, and Codex does in its desktop app, CLI and editor extension. See what MCP is and the Codex client page.
Is Codex open source?
The Codex CLI is: its GitHub repository is licensed under Apache-2.0.
Where can I run each one?
Antigravity has an app for macOS, Windows and Linux, a CLI, IDE extensions and an SDK. Codex's pricing page lists the web, the CLI, the IDE extension and iOS under Plus, and the ChatGPT desktop app.
Antigravity vs Codex vs Claude Code?
See Claude Code vs Codex for the other side of this match-up. All three support MCP; see MCP tools for what MCP adds.
Information
updated Nov 3, 2026
- Transports
- stdio, Streamable HTTP
- Config file (all)
~/.codex/config.toml- MCP docs
- developers.openai.com
Sources
Docs, issue trackers and discussions this page is built from.
Show all 11Hide
- Google Antigravity · antigravity.google
- Choose a model · antigravity.google
- Google AI plans · gemini.google
- Codex pricing · learn.chatgpt.com
- Plans · antigravity.google
- Antigravity pricing · antigravity.google
- Model Context Protocol (MCP) · antigravity.google
- Agent skills · antigravity.google
- MCP in Codex · learn.chatgpt.com
- Plugins · learn.chatgpt.com
- openai/codex · github.com