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Claude Opus vs Sonnet

Claude Opus 4.7 vs Sonnet 4.6 compared: benchmark differences, real-world task quality, agentic reliability, pricing, and when Opus is actually worth 5x.

Updated May 2026 · 7 min read
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Claude Opus 4.7 costs $15/$75 per 1M tokens — five times Sonnet 4.6 ($3/$15). Anthropic positions Opus as the model for hardest tasks: long agentic loops, deep reasoning, complex code refactors. The honest answer for most users is 'use Sonnet by default; reach for Opus when you've measured a real quality gap.' This page lays out exactly when that gap appears.

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Option 1

Claude Opus 4.7

Anthropic's flagship — best on hardest tasks, longest agentic horizons.

Best for

Production agents that run unsupervised for 30+ steps, hard SWE-bench tasks, research-grade analysis where quality justifies 5x cost.

Pros

  • Highest SWE-bench Verified, Aider, MMLU scores.
  • Best agentic reliability over long horizons.
  • Reasoning depth on math, logic, multi-step problems.
  • Same 1M context as Sonnet.
  • Strongest instruction-following on adversarial prompts.

Cons

  • 5x the cost of Sonnet.
  • Slightly slower (a couple of seconds for short outputs).
  • Diminishing returns on routine tasks.

Option 2

Claude Sonnet 4.6

Anthropic's daily driver — 95% of Opus quality at 1/5 the price.

Best for

Everything that isn't on Opus's narrow 'hardest tasks' list. Default for coding, writing, agents up to ~30 steps, chat.

Pros

  • $3/$15 per 1M — much friendlier on production budgets.
  • Faster than Opus.
  • 1M context.
  • Strong tool use, vision, prompt caching.
  • Hits 95%+ of Opus quality on most tasks.

Cons

  • Falls behind on the hardest agentic / reasoning tasks.
  • Less reliable on 30+ step loops than Opus.
  • 5-point gap on top SWE-bench tasks.

The verdict

Use Sonnet 4.6 for everything by default. Reach for Opus 4.7 when (a) you've measured a real quality gap on your task, (b) your agent runs unsupervised for many steps, or (c) you're doing hard reasoning where the answer can't easily be verified. For most code work, Sonnet wins on cost-quality even when Opus is technically a few points better.

Run the numbers yourself

Plug your own inputs into the free tools below — no signup, works in your browser, nothing sent to a server.

Free toolClaude vs DeepSeek Cost CalculatorSide-by-side cost for Claude Opus 4.7, Sonnet 4.6, Haiku 4.5 vs DeepSeek V3.2 and R1 — at your real volume.Open tool →Free toolFrontier AI Model TrackerLive tracker of every frontier AI model: Claude 4.x, GPT-5, Gemini 3 Pro, DeepSeek R1/V3.2, Kimi K2, Grok 4, Llama 4, Qwen 3.5, Mistral Large 3.Open tool →

Frequently asked questions

Is Opus 5x better than Sonnet?

No — closer to 5% better on most benchmarks. The 5x price reflects Opus being the absolute best, not 5x the quality. Use Opus where the marginal quality matters; use Sonnet everywhere else.

When should I always pick Opus?

Long-running agents (30+ steps), hard reasoning where you can't easily verify the output, and code refactors that touch many files. For these, Opus's reliability advantage compounds.

Can I mix Opus and Sonnet in the same agent?

Yes, and many production setups do. Sonnet handles routine steps; Opus handles the hardest reasoning step or the final synthesis. Saves 60-80% of the Opus-only bill at similar quality.

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