Claude 4.6 Sonnet vs Claude 4.5 Haiku

1. Most capable Sonnet model yet

• Anthropic describes Sonnet 4.6 as its most capable Sonnet model.
• It is a full upgrade across coding, computer use, long-context reasoning, agent planning, knowledge work, and design.

2. Stronger coding and professional task performance at Sonnet pricing

• Pricing remains at $3/M input and $15/M output, matching Sonnet 4.5.
• Anthropic says early-access developers strongly preferred it to Sonnet 4.5, and often even to Opus 4.5 for practical work.

3. Long-context, agent-friendly reasoning

• Supports up to a 1M token context window in beta.
• Anthropic reports better consistency, fewer false claims of success, fewer hallucinations, and more reliable follow-through on multi-step tasks.

4. Modern API controls for adaptive work

• Supports adaptive thinking and the effort parameter for balancing speed, cost, and depth.
• Gains dynamic filtering for web search and web fetch, helping agent workflows keep only relevant information in context.

1. Frontier-level coding at small-model speed

• Similar coding performance to Claude Sonnet 4 at one-third the cost.
• Runs 4-5x faster than Sonnet 4.5 for many tasks.
• Ideal for real-time pair programming, prototyping, and rapid iteration.

2. Excellent computer-use abilities

• Surpasses Claude Sonnet 4 in certain computer-control tasks.
• Great for agents requiring low-latency tool use (Chrome automation, coding agents, etc.).

3. Perfect for real-time, low-latency applications

• Chat assistants
• Customer support agents
• Interactive development loops
• Multi-agent orchestration

4. Works seamlessly with Sonnet 4.5 in hybrid agent setups

• Sonnet 4.5 plans complex workflows.
• Haiku 4.5 executes subtasks in parallel for speed and cost-efficiency.

5. High alignment & safest Claude model by metric

• Lower misaligned behavior rates than Haiku 3.5, Sonnet 4.5, and Opus 4.1.
• Limited CBRN risk → released under AI Safety Level 2 (ASL-2).