Claude Opus 4.8 in Short
Claude Opus 4.8 is Anthropic's flagship — the model to reach for on the hardest reasoning, long-horizon agentic work, and high-stakes writing/code where quality beats cost. It's powerful and priced like it. Here's an honest take on where it wins and where a cheaper tier is smarter.
Pricing
| Input (1M) | Output (1M) | |
|---|---|---|
| Opus 4.8 | $5.00 | $25.00 |
| Sonnet 4.6 | $3.00 | $15.00 |
| Haiku 4.5 | $1.00 | $5.00 |
Batch can cut ~50% and prompt caching up to ~90% on repeated prefixes — see prompt caching. Full breakdown in Claude Opus API pricing.
What It's Best At
- Deep, multi-step reasoning where a cheaper model drops details.
- Long-horizon agents that must stay coherent over many steps.
- High-stakes output — legal/financial analysis, senior-level code review, nuanced writing.
How It Compares to GPT-5.6
OpenAI's July 2026 GPT-5.6 launch reset the coding leaderboard: OpenAI reports Sol tops the Artificial Analysis Coding Agent Index at 80, and even its budget Luna tier claims to outperform Opus 4.8. Some testers still prefer Anthropic's models for judgment and writing quality. Translation: for pure coding-agent throughput, GPT-5.6 Sol is the new benchmark; for reasoning depth and writing, Opus 4.8 remains a top pick. Test both on your tasks — see Claude vs GPT and best coding LLM API.
When NOT to Use Opus
Most workloads don't need it. At $25/1M output, Opus is wasteful for bulk classification, summarization or chat — route those to Sonnet 4.6 or Haiku 4.5, or DeepSeek V4 Flash. The winning pattern: default to a mid tier, escalate to Opus for the hard 5–10% — how to reduce AI API costs.
Call It
curl -X POST https://api.linkmodel.ai/v1/chat/completions \
-H "Authorization: Bearer $LINKMODEL_API_KEY" -H "Content-Type: application/json" \
-d '{ "model": "claude-opus-4-8", "messages": [{"role":"user","content":"Audit this architecture for failure modes: ..."}] }'Through LinkModel you can call Opus 4.8 and instantly A/B against GPT-5.6 or Gemini 3 Pro on the same key — up to 30% below official. Confirm the chat endpoint in the docs. New to keys? How to get a Claude API key.
Bottom Line
Opus 4.8 is a genuine flagship for reasoning depth and high-stakes work, but GPT-5.6 has pressured it on coding and price. Use Opus surgically for the hardest tasks, cheaper tiers for the rest — and benchmark on your own prompts before committing.
Start free with a $1 credit and compare Opus 4.8 head-to-head.