Claude Opus vs Claude Sonnet
The one most Claude users get wrong by defaulting up. Sonnet 5.5 handles the large majority of real work at half Opus 5.5's price, with the same million-token context. Opus earns its cost on long autonomous runs and architectural reasoning, not on the routine edits people usually point it at.
| Claude Opus | Claude Sonnet | |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Current release | Opus 5.5 | Sonnet 5.5 |
| Tier | Frontier | Balanced |
| Context | 1M | 1M |
| Cost | Premium | Moderate |
| Modalities | text, vision | text, vision |
| Open weights | No | No |
Cost is a tier, not a quote, providers change prices often. Check Anthropic and Anthropic before you commit. Last updated 2026-10-21.
Which one to pick
Claude OpusAnthropic · Opus 5.5
Agentic coding and multi-step engineering work, near the ceiling at a fraction of the price
Reach for it when- Long agent runs with no human in the loop
- Architecture decisions and gnarly debugging
Claude SonnetAnthropic · Sonnet 5.5
The default for most work, reads code like a senior engineer at a fair price
Reach for it when- Day-to-day coding, editing and refactoring
- Anything you run at volume
Related comparisons
- Claude Opus vs GPT AstraThe practical version of the frontier question, because Opus 5.5 costs well under half what Astra does, $4 and $20 per million tokens against $10 and $50, and Anthropic recommends it as the default for most workloads.
- Claude Opus vs GPT SolTwo mid-frontier models, now that GPT-6 Astra sits above Sol and Claude Fable 5.1 sits above Opus.
- Claude Opus vs Gemini ProTwo different bets.
- Claude Opus vs GrokBoth are pitched at agentic coding.
- Claude Sonnet vs GPT TerraThe workhorse tier, where most production traffic actually runs.
- Claude Sonnet vs Gemini ProA tier-crossing comparison people make on price.