- Provider
- Anthropic
- Family
- Claude 4.x
- Context window
- 200K tokens
- Modality
- text, vision, tool use
- Knowledge cutoff
- January 2026
- Last updated
- 2026-04-19
At a glance
Claude Sonnet 4.6 is the workhorse Claude model — strong reasoning, good instruction following, significantly cheaper and faster than Opus, used for the bulk of production AI traffic.
Strengths
- Strong reasoning at a fraction of Opus cost
- Fast enough for interactive chat UX
- Good instruction following for structured outputs
Weaknesses
- Not the best choice for the hardest reasoning steps — escalate to Opus
- Less capable than GPT-5.5 on some specific math/STEM benchmarks
Best for
- Default chat and agent workloads
- Document QA and retrieval answers
- Structured extraction at interactive latency
Why Sonnet is the default
For most production AI work, Sonnet 4.6 is the right first choice. It reasons well enough for agent loops, chat surfaces, and retrieval pipelines, and it costs a fraction of Opus. A typical WolfAI stack runs 70–80% of requests on Sonnet, escalating up to Opus for hard reasoning and down to Haiku for simple extraction.
Sonnet in routing strategies
In a routed stack, Sonnet sits in the middle tier. The router classifies each request and sends short extractions to Haiku, default interactive traffic to Sonnet, and escalations to Opus. That mix keeps p50 latency low and cost per request manageable.
Frequently asked questions
Is Claude Sonnet 4.6 good for production?
Yes. Sonnet 4.6 is Anthropic's workhorse tier and is widely used for production chat surfaces, agent loops, and retrieval answers. It is cheaper and faster than Opus while still reasoning well enough for most tasks.
When should I pick Opus over Sonnet?
Move from Sonnet to Opus 4.7 when a task's failure cost is much higher than the extra inference cost — architectural code reviews, long-document synthesis, and hard agent planning are typical examples.