Clawy / Guides / Which Claude model

Which Claude model should you use?

Opus 4.8, Sonnet 4.6, or Haiku 4.5 — a practical pick-per-task guide, not a benchmark dump.

Most teams over-spend by defaulting every call to the biggest model. The three current Claude tiers span a 5× price range, and the right answer is usually "the cheapest one that clears the task." Here's how they compare and how to decide.

The lineup at a glance

ModelPrice (in / out per 1M)ContextBest at
Haiku 4.5$1 / $5200Kfast, cheap, high-volume: classification, extraction, routing, simple chat
Sonnet 4.6$3 / $151Mthe balanced workhorse: most production tasks, coding, summarization, RAG
Opus 4.8$5 / $251Mhardest reasoning, long-horizon agents, deep research, tricky debugging

(Anthropic also offers Claude Fable 5 — its most capable model, priced above Opus — for the most demanding long-horizon work. For everyday production, the three above cover the vast majority of use cases.)

A 20-second decision flow

Is the task simple and high-volume (label this, extract that, route, classify)? → Haiku 4.5. It's 5× cheaper than Opus and plenty smart for these.

Is it a normal production task — coding help, summarizing, answering over retrieved docs, a chatbot? → Sonnet 4.6. Best balance of intelligence, speed, and cost.

Does it need genuine multi-step reasoning, agentic tool-use over a long horizon, or it's just hard and getting it right matters more than cost? → Opus 4.8.

Not sure? Start one tier down from your instinct and only escalate if quality misses. You'll be right more often than you expect — and cheaper.

Don't forget thinking & effort

On Sonnet 4.6 and Opus 4.8 you can dial reasoning depth with adaptive thinking and the effort parameter (lowmax). A cheaper model at higher effort sometimes beats a pricier one at low effort — and costs less. Haiku doesn't support the effort parameter, which is part of why it's the speed/cost tier rather than the reasoning tier.

The cost difference is bigger than the price tags suggest

Because output is billed 5× higher than input, and bigger models tend to be used on bigger prompts, the real bill gap between Haiku and Opus on the same workload is often more than 5×. If you're running serious volume, the model-selection decision dwarfs almost every other cost lever.

→ See the actual numbers. Plug each model into the free cost / margin calculator with your real prompt sizes and compare cost per call side by side.

Rule of thumb: Haiku for volume, Sonnet for most things, Opus for the hard 10%. Measure, then escalate deliberately.

→ Or let routing decide. Clawy's $0.04 auto tier picks a cost-optimized model per call over x402 — USDC per request, no API keys. 5-minute quickstart → → Get the AI API Pricing Kit (€19). Compare model costs in a real Excel model, plus drop-in margin-guard code and an offline calculator — so the model you pick never costs more than you charge.