Claude Opus 5 vs GPT-5.6 Sol: which flagship reasoning model is cheaper?
On raw price, Claude Opus 5 wins marginally (cheaper output). Pick whichever model is smarter at your specific workload - the cost gap is small enough that quality should be the tiebreaker.
Same-tier flagship reasoning from Anthropic and OpenAI, almost identical input pricing.
Claude Opus 5 and GPT-5.6 Sol are the two top-tier reasoning models from Anthropic and OpenAI's 2026 generation. Their input prices match exactly at $5.00 per million. The deciding factor on cost is the output price, where Opus 5 is ~17% cheaper.
By TechCompare · Updated
Cost Comparison
Based on 100,000 input tokens (50% cached), 5,000 output tokens, and 100 requests.
Side-by-side specs
| Spec | Claude Opus 5 | GPT-5.6 Sol |
|---|---|---|
| Input Cost (per M) | $5.00 | $5.00 |
| Output Cost (per M) | $25.00 (better on this spec) | $30.00 |
| Cached Input (per M) | $0.50 | $0.50 |
| Batch Discount | 50% | 50% |
| Context Window | 1M | 1.05M (better on this spec) |
How they differ
Claude Opus 5 is priced at $5.00 per million input tokens and $25.00 per million output tokens, with a 90% caching discount ($0.50 per million) and a 50% batch discount. GPT-5.6 Sol is priced at $5.00 per million input tokens and $30.00 per million output tokens, also with a 90% caching discount ($0.50 per million) and a 50% batch discount. For a typical 100K input + 10K output request, Opus 5 costs $0.75 and Sol costs $0.80 - a small gap at single-request scale, but a $50K difference over a million calls. On capability, both target the same 'hardest reasoning tier' but lean on different strengths: Opus 5's long-context agentic tool use vs Sol's math and code synthesis.
Verdict
On raw price, Claude Opus 5 wins marginally (cheaper output). Pick whichever model is smarter at your specific workload - the cost gap is small enough that quality should be the tiebreaker.
Which should you pick?
Choose Claude Opus 5
Long-context agentic chains, tool-heavy automations, and Anthropic-flavored instruction following. Opus 5's 1M context and mature tool-use ecosystem pay off when you push the model hard.
Choose GPT-5.6 Sol
Math-heavy scientific reasoning, code synthesis, and pipelines where OpenAI's tooling ecosystem is already wired in. Sol's premium output cost is real but the 90% cache discount absorbs it on cache-heavy workloads.