Claude Sonnet 4

Model Overview

Claude Sonnet 4 is a legacy mid-tier model released by Anthropic on May 22, 2025. It was the first of the generation 4 models, targeting fast responses, broad knowledge retrieval, and reliable everyday reasoning. It featured a 200,000-token context window and supported text, image, and code modalities. Note: As of June 15, 2026, Claude Sonnet 4 has been officially retired by Anthropic.

Capabilities

• Broad Knowledge Retrieval: Designed to access and synthesize information effectively across a wide array of topics.
• General-Purpose Tasks: Optimized for balanced performance on everyday reasoning and professional tasks.
• Multimodal Processing: Capable of understanding and generating insights from text, images, and code.

Example Use Cases

• Customer support automation and intelligent chatbots.
• Routine coding assistance, code review, and bug fixing.
• Summarization and data extraction from medium-length documents (up to 200K tokens).
• Drafting emails, reports, and everyday professional communications.

Performance & Benchmarks

As an early generation 4 model, Sonnet 4 provided a strong baseline of speed and intelligence. However, it has since been surpassed by iterative updates (such as Sonnet 4.5) and the current generation (Sonnet 5), which offer significantly improved agentic coding and reasoning benchmark scores.

Intended Use & Limitations

It was originally intended for balanced, cost-effective deployments where extreme complex reasoning (the domain of Opus) was not required. Limitation: This model is officially retired and no longer available for new production workloads. Developers are encouraged to migrate to Claude Sonnet 5.

About Anthropic

Anthropic is an AI safety and research company focused on building reliable, interpretable, and steerable AI systems. They are the creators of the Claude family of models, known for prioritizing safety and alignment alongside frontier capability.