Try another model on a real task in Reason
Open Reason on the web or the Mac app
Sign in at reasonmachines.com, or download the Reason Mac app for macOS from reasonmachines.com/download and sign in there. Both open the same Sessions.
Connect the plans you already pay for
In Settings › Models, choose Sign in with ChatGPT to run OpenAI models on your ChatGPT Plus, Pro or Business plan, and add any other subscriptions or API keys you use. Reason runs on your own accounts first; a Reason plan's credits cover the rest.
Give it a task you know well
Ask Reason for a task you already know the answer to, such as a review of your current branch, and compare the answer with Claude Code's own. Switch the model in the composer to compare providers on the same task.
Alternatives at a glance
| Made by | Open source | Models | Free option | Paid | |
|---|---|---|---|---|---|
| Codex | OpenAI | CLI under Apache-2.0 | OpenAI models; open models through codex --oss with Ollama | ChatGPT Free and Go include Codex: GPT-6 Luna in the desktop app, subject to rollout | ChatGPT Plus $20 a month, Pro from $100 |
| opencode | The opencode project | MIT | 75+ providers and local models, Ollama included; ChatGPT Plus, GitHub Copilot and GitLab Duo subscriptions work | The tool is free; bring your own provider or a local model | Optional OpenCode Go from $10 a month |
| Google Antigravity | Not stated | Gemini models; third-party models on Google AI Ultra | $0 individual plan with basic weekly rate limits | Google AI Pro $20 a month; Ultra $100 or $200 a month | |
| Gemini CLI | Apache-2.0 | Gemini | None for individuals since June 18, 2026: free and Google AI Pro/Ultra access moved to Antigravity CLI | Gemini Code Assist Standard and Enterprise, or paid Gemini API keys | |
| Reason | Reason Machines | No | Reason's models, plus ChatGPT, Copilot and other subscriptions or API keys you connect | None; the agent needs a plan | Pro $50 a month, Max $200 a month |
| Local models via Ollama | Ollama | Depends on the model | Open models on your own hardware, or Ollama's cloud models | Free on your own hardware | Optional: Ollama's cloud models |
Prices are the vendors' US list prices and change often; follow the links to check them. Local models need a machine that can run them with a long context window; Ollama recommends 64k tokens or more for coding agents.
- OpenAI: Codex pricing and usage limits
- openai/codex on GitHub (Apache-2.0)
- opencode docs: providers
- anomalyco/opencode on GitHub (MIT)
- opencode docs: OpenCode Go
- Google Antigravity: pricing
- Google Antigravity blog: changes to Antigravity plans
- google-gemini/gemini-cli on GitHub
- Reason docs: plans
- Ollama docs: Codex
Free Claude Code alternatives
Codex on ChatGPT Free: OpenAI includes Codex in the Free plan with GPT-6 Luna in the desktop app, subject to rollout; Codex Cloud is not included.
Google Antigravity's individual plan is $0 a month with basic weekly rate limits. Gemini CLI is no longer the free route: Google moved free individual access to Antigravity CLI on June 18, 2026.
opencode with a local model: opencode is free and MIT-licensed, and connects to Ollama on your computer. Codex can do the same with codex --oss. You pay only for your hardware, and quality depends on the model you can run.
You can't use a Claude Pro or Max subscription in opencode or other third-party tools: Anthropic prohibits it, and opencode removed those plugins in version 1.3.0.
You don't have to choose
Keep Claude Code for what it does best, and use Reason's web or Mac app for second opinions, parallel Sessions, or a task when Claude Code is out of usage. Reason runs on the model accounts you connect, such as your ChatGPT plan or Copilot subscription, so you pick the model per task.
Open-source and local-LLM alternatives in 2026
Free and open source: opencode (MIT), Aider (Apache-2.0), Cline (Apache-2.0) and OpenHands (MIT). All four work with local models: opencode and Cline through Ollama, Aider with almost any LLM including local ones, and OpenHands with the agent and model you choose. A local model costs nothing per token, but quality depends on the model your hardware can run.
Cheaper than Claude Code: Codex is included in ChatGPT Free and Go, Cursor has a free plan and Plus at $8 a month, GitHub Copilot Pro is $10 a month, and Google Antigravity has a $0 individual plan.
Questions
What is the best free alternative to Claude Code?
It depends on what you have. Codex is included in ChatGPT Free, Antigravity has a $0 individual plan with weekly rate limits, and opencode or Codex can run open models locally through Ollama at no cost beyond your hardware.
Is Gemini CLI still free?
Not for individuals. Gemini CLI's README says free individual access and Google AI Pro and Ultra moved to Antigravity CLI on June 18, 2026; Gemini CLI now serves Code Assist licenses and paid API keys.
Can I use my Claude subscription in opencode?
No. Anthropic doesn't permit third-party tools to route requests through Free, Pro, Max or Ultra plan credentials, and opencode stopped bundling those plugins in 1.3.0. opencode works with an Anthropic API key, other providers or local models.
Is Reason free?
No. Reason's coding agent needs a plan: Pro is $50 a month and Max $200 a month. Models you run on your own connected accounts count against those accounts.