---
title: Claude Sonnet 4.0
description: Claude Sonnet 4.0 by Anthropic — first Claude 4 Sonnet, stable and widely used.
---

# Claude Sonnet 4.0

**Key:** `claude-sonnet-4-0`  
**Provider:** [Anthropic](/en/providers/anthropic/)  
**Support:** `runnable`

## Capabilities

chat · reasoning · tools

## Specifications

| Field | Value |
|-------|-------|
| Context window | 200 000 tokens |
| Input modalities | text |
| Output modalities | text |

## When to use

The first Claude 4 Sonnet model. Still supported for lenses pinned to this version. Migrate to `claude-sonnet-4-6` for improved performance on new lenses.

## Provider documentation

→ [Anthropic model overview](https://docs.anthropic.com/en/docs/about-claude/models/overview)
