Claude Code Model Configuration | Claude Help Center

This guide shows you three ways to change which Claude model you're using with Claude Code: the quick /model command for instant changes, the --model flag for one-time session changes, and environment variables to set your preferred model as the permanent default.

Easiest Method: Use /model Command

The simplest way to change models is to use the /model command directly within Claude Code. This works immediately without restarting your terminal.

Start Claude Code: claude
Type /model and choose your desired model from the interactive menu.
Your model change takes effect immediately.

Note: You can check your current model anytime by running /status in Claude Code.

Supported Models

Opus 4.5, claude-opus-4-5-20251101
Haiku 4.5, claude-haiku-4-5-20251001
Sonnet 4.5, claude-sonnet-4-5-20250929 (default)
Opus 4.1, claude-opus-4-1-20250805
Opus 4, claude-opus-4-20250514
Sonnet 4, claude-sonnet-4-20250514
Haiku 3.5, claude-3-5-haiku-20241022

⚠️ Model Access: When using a Pro plan with Claude Code, you will only be able to use Opus models after enabling and purchasing extra usage.

Change model for current session only

Use the --model flag when starting Claude Code.

Start a fresh Terminal session.
Enter the following commands (depending on the model you’d like to use for that session):
- For Opus 4.5: claude --model claude-opus-4-5-20251101
- For Haiku 4.5: claude --model claude-haiku-4-5-20251001
- For Sonnet 4.5: claude --model claude-sonnet-4-5-20250929
- For Opus 4.1: claude --model claude-opus-4-1-20250805
- For Opus 4: claude --model claude-opus-4-20250514
- For Sonnet 4: claude --model claude-sonnet-4-20250514
- For 3.5 Haiku: claude --model claude-3-5-haiku-20241022

Change default model for all future sessions

Step 1) Check your shell type by running: echo $SHELL

/bin/zsh → You're using zsh (macOS default)
/bin/bash → You're using bash (Linux default)

Step 2) Add model setting to your shell config:

For ZSH users (macOS)

Opus 4.5: echo 'export ANTHROPIC_MODEL="claude-opus-4-5-20251101"' >> ~/.zshrc
Haiku 4.5: echo 'export ANTHROPIC_MODEL="claude-haiku-4-5-20251001"' >> ~/.zshrc
Sonnet 4.5: echo 'export ANTHROPIC_MODEL="claude-sonnet-4-5-20250929"' >> ~/.zshrc
Opus 4.1: echo 'export ANTHROPIC_MODEL="claude-opus-4-1-20250805"' >> ~/.zshrc
Opus 4: echo 'export ANTHROPIC_MODEL="claude-opus-4-20250514"' >> ~/.zshrc
Sonnet 4: echo 'export ANTHROPIC_MODEL="claude-sonnet-4-20250514"' >> ~/.zshrc
3.5 Haiku: echo 'export ANTHROPIC_MODEL="claude-3-5-haiku-20241022"' >> ~/.zshrc

For BASH users (Linux)

Opus 4.5: echo 'export ANTHROPIC_MODEL="claude-opus-4-5-20251101"' >> ~/.bashrc
Haiku 4.5: echo 'export ANTHROPIC_MODEL="claude-haiku-4-5-20251001"' >> ~/.bashrc
Sonnet 4.5: echo 'export ANTHROPIC_MODEL="claude-sonnet-4-5-20250929"' >> ~/.bashrc
Opus 4.1: echo 'export ANTHROPIC_MODEL="claude-opus-4-1-20250805"' >> ~/.bashrc
Opus 4: echo 'export ANTHROPIC_MODEL="claude-opus-4-20250514"' >> ~/.bashrc
Sonnet 4: echo 'export ANTHROPIC_MODEL="claude-sonnet-4-20250514"' >> ~/.bashrc
3.5 Haiku: echo 'export ANTHROPIC_MODEL="claude-3-5-haiku-20241022"' >> ~/.bashrc

Step 3) Apply the changes:

For ZSH: source ~/.zshrc
For BASH: source ~/.bashrc

Step 4) Close Terminal completely, then reopen it.

Step 5) Start Claude Code in a fresh Terminal session: claude.

Now your chosen model will be the default for all future Claude Code sessions.

How up-to-date is Claude's training data?

Using Claude Code with your Team or Enterprise plan

Release Notes

Claude for Chrome Release Notes

Using Claude in Microsoft Foundry