High-volume, cost-sensitive work
Either one
Both cost $4.00 per million tokens on a typical mix of three input tokens for every output token.
Claude Sonnet 5.5 vs GPT-6 Sol: price, context and capabilities
Choose Claude Sonnet 5.5 for reused prompts and documents (RAG, agents), the hardest reasoning tasks and the most recent knowledge; on the other points the two are level or the data is missing.
In short
- Both cost the same at the headline price ($4.00 / 1M tokens).
- GPT-6 Sol reads more per request: 1.05M tokens against 1M.
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Reused prompts and documents (RAG, agents)
Choose Claude Sonnet 5.5
Claude Sonnet 5.5 charges $0.10 per million cached input tokens, against $0.20 for GPT-6 Sol.
Hardest reasoning tasks
Choose Claude Sonnet 5.5
Claude Sonnet 5.5 scores 56 on the Artificial Analysis Intelligence Index, against 47.6 for GPT-6 Sol.
Reasoning over long documents
Either one
They are practically level on Long-context reasoning (AA-LCR) (82.7% and 83.7%).
Most recent knowledge
Choose Claude Sonnet 5.5
Claude Sonnet 5.5 was trained on data up to June 2026, against April 2026 for GPT-6 Sol.
Monthly cost at three volumes
| Volume | Claude Sonnet 5.5 | GPT-6 Sol | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $4.50 | $4.50 | = |
| Production: 20M input, 5M output tokens | $90.00 | $90.00 | = |
| Scale: 500M input, 100M output tokens | $2,000 | $2,000 | = |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| Claude Sonnet 5.5 | GPT-6 Sol | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Category | Language models | Language models |
| Status | Generally available | Generally available |
| Headline price | $4.00 / 1M tokens | $4.00 / 1M tokens |
| Input | $2.00 / 1M tokens | $2.00 / 1M tokens |
| Output | $10.00 / 1M tokens | $10.00 / 1M tokens |
| Cached input | $0.10 / 1M tokens | $0.20 / 1M tokens |
| Context window | 1M | 1.05M |
| Max output | 128k | 128k |
| Released | September 2026 | Sep 22, 2026 |
| Knowledge cutoff | June 2026 | April 2026 |
| Licence | Proprietary | Proprietary |
| Capabilities | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API |
| API model id | claude-sonnet-5-5 | gpt-6-sol |
Benchmarks side by side
Leader in bold.
| Benchmark | Claude Sonnet 5.5 | GPT-6 Sol |
|---|---|---|
| Intelligence Index | 56 | 47.6 |
| SciCode | 61% | 57.6% |
| Humanity's Last Exam | 55% | 47.9% |
| Long-context reasoning (AA-LCR) | 82.7% | 83.7% |
| MMMU-Pro (visual reasoning) | No data | 82.9% |
Independent evaluations by Artificial Analysis, run the same way for every model, at the reasoning setting shown. Percentages unless marked as an index.
Frequently asked questions
Should I choose Claude Sonnet 5.5 or GPT-6 Sol?
Choose Claude Sonnet 5.5 for reused prompts and documents (RAG, agents), the hardest reasoning tasks and the most recent knowledge; on the other points the two are level or the data is missing.
Which is cheaper, Claude Sonnet 5.5 or GPT-6 Sol?
Both cost the same at the headline price ($4.00 / 1M tokens).
Which has the larger context window, Claude Sonnet 5.5 or GPT-6 Sol?
GPT-6 Sol reads more per request: 1.05M tokens against 1M.
What is the difference between Claude Sonnet 5.5 and GPT-6 Sol?
Claude Sonnet 5.5 is made by Anthropic and GPT-6 Sol by OpenAI. Both cost the same at the headline price ($4.00 / 1M tokens). GPT-6 Sol reads more per request: 1.05M tokens against 1M.
How much do Claude Sonnet 5.5 and GPT-6 Sol cost per month?
At 20 million input and 5 million output tokens a month, Claude Sonnet 5.5 costs $90.00 and GPT-6 Sol costs $90.00, at standard rates.