Claude Change Sonnet 4.6 to have 1 million Token context

 

In Sonnet 4.6 of Claude the default is 200K for the context size. 
You can up it to 1 million by tweaking the ~/.claude/settings.json file

Change it!

Update claude

> claude update

Start up Claude

> claude

And run /context

> /context

 

Here you can see I am running Sonnet 4.6 and the size of my content is 200K.

Now stop Claude and edit ~/.claude/settings.json

> vi ~/.claude/settings.json

And add this to the json

"model": "claude-sonnet-4-6[1m]"

 

Now start up Claude again

> claude

And run /context

> /context

 

And now my context size is 1 million!

Now at this point I would not recommend 1 million for sonnet 4.6, unless you really need it.  A smaller context size of 200K can keep you more focused, but 1 million may be needed if you are doing some massive analysis or long runs.

See Claude 1M Context Window Goes GA: What Changes for Claude Code Users https://claudefa.st/blog/guide/mechanics/1m-context-ga [1]

 

 

What about for Opus 4.7?

Opus 4.7 is the most intelligent version Claude offers but it also costs more.  So how can we change to 4.7?

Stop Claude and edit ~/.claude/settings.json

> vi ~/.claude/settings.json

And add this to the JSON

"model": "claude-opus-4-7"

 

Start Claude

> claude

 

And run /context

> /context

 

It looks like Opus 4.7 defaults to 1 million

There is a way!

Stop Claude and edit ~/.claude/settings.json

> vi ~/.claude/settings.json

And add this to the JSON

"env": {       "CLAUDE_CODE_DISABLE_1M_CONTEXT": "1" }

 

Start Claude

> claude

And run /context

> /context

 

References

 

[1]       Claude 1M Context Window Goes GA: What Changes for Claude Code Users
             https://claudefa.st/blog/guide/mechanics/1m-context-ga
            Accessed 05/2026