Claude Sonnet 5.5 (Adaptive Reasoning, High Effort, Default Fallback)

What is Claude Sonnet 5.5 (Adaptive Reasoning, High Effort, Default Fallback)?

Claude Sonnet 5.5 (Adaptive Reasoning, High Effort, Default Fallback) is an AI model developed by Anthropic, classified as a text model. It focuses on text processing and natural language generation. As a proprietary model, it is available via Anthropic's cloud API.

Pricing & Costs in 2026

Claude Sonnet 5.5 (Adaptive Reasoning, High Effort, Default Fallback) is usage-based, priced at $2/1M input tokens and $10/1M output tokens. For context: 1 million tokens is approximately 750,000 words, or about 10 average-length books. The mid-range pricing balances quality and cost for most professional applications.

Benchmarks & Performance

Claude Sonnet 5.5 (Adaptive Reasoning, High Effort, Default Fallback) was evaluated on 1 different benchmarks, covering categories like overall. Results show moderate performance across available evaluations.

It's important to note that benchmarks measure specific aspects and don't capture the full user experience. Factors like instruction adherence, behavior in long conversations, and real-world task quality vary significantly between models and aren't always reflected in standard scores.

Recommended Use Cases

Claude Sonnet 5.5 (Adaptive Reasoning, High Effort, Default Fallback) specializes in text, offering advanced capabilities for creating and processing text content.

Comparison with Alternatives

In the 2026 AI model ecosystem, Claude Sonnet 5.5 (Adaptive Reasoning, High Effort, Default Fallback) competes directly with similarly capable models. Key competitors include GPT (OpenAI), Gemini (Google), and open source models like Llama (Meta) and DeepSeek. The choice between models depends on the specific use case, budget, latency requirements, and need for features like multimodality and tool calling.

For a detailed side-by-side comparison, use our comparison tool or check the overall model ranking.