High-volume, cost-sensitive work
Choose GPT-5.6 Sol
GPT-5.6 Sol costs 20% less on a typical mix of three input tokens for every output token ($8.00 against $10.00 per million tokens).
Claude Opus 4.8 vs GPT-5.6 Sol: price, context and capabilities
Choose Claude Opus 4.8 for tool use and support agents. Choose GPT-5.6 Sol for high-volume, cost-sensitive work, writing and code generation, reused prompts and documents (RAG, agents), the hardest reasoning tasks, agentic coding, reasoning over long documents and the latest release.
In short
- GPT-5.6 Sol is 20% cheaper than Claude Opus 4.8 at the headline price ($8.00 / 1M tokens vs $10.00 / 1M tokens).
- GPT-5.6 Sol reads more per request: 1.05M tokens against 1M.
- GPT-5.6 Sol is the newer model (Jul 9, 2026, against May 2026).
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Writing and code generation
Choose GPT-5.6 Sol
GPT-5.6 Sol charges $20.00 per million output tokens, against $25.00 for Claude Opus 4.8. Output dominates the bill when answers are long.
Reused prompts and documents (RAG, agents)
Choose GPT-5.6 Sol
GPT-5.6 Sol charges $0.40 per million cached input tokens, against $0.50 for Claude Opus 4.8.
Hardest reasoning tasks
Choose GPT-5.6 Sol
GPT-5.6 Sol scores 47 on the Artificial Analysis Intelligence Index, against 41.8 for Claude Opus 4.8.
Agentic coding
Choose GPT-5.6 Sol
GPT-5.6 Sol scores 65.9% on Terminal-Bench Hard, against 58.3% for Claude Opus 4.8.
Tool use and support agents
Choose Claude Opus 4.8
Claude Opus 4.8 scores 94.4% on τ²-Bench (agentic tool use), against 85.1% for GPT-5.6 Sol.
Reasoning over long documents
Choose GPT-5.6 Sol
GPT-5.6 Sol scores 84% on Long-context reasoning (AA-LCR), against 77.7% for Claude Opus 4.8.
Latest release
Choose GPT-5.6 Sol
GPT-5.6 Sol is the newer release (Jul 9, 2026, against May 2026 for Claude Opus 4.8).
Monthly cost at three volumes
| Volume | Claude Opus 4.8 | GPT-5.6 Sol | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $11.25 | $9.00 | GPT-5.6 Sol, $2.25 less |
| Production: 20M input, 5M output tokens | $225.00 | $180.00 | GPT-5.6 Sol, $45.00 less |
| Scale: 500M input, 100M output tokens | $5,000 | $4,000 | GPT-5.6 Sol, $1,000 less |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| Claude Opus 4.8 | GPT-5.6 Sol | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Category | Language models | Language models |
| Status | Legacy | Generally available |
| Headline price | $10.00 / 1M tokens | $8.00 / 1M tokens |
| Input | $5.00 / 1M tokens | $4.00 / 1M tokens |
| Output | $25.00 / 1M tokens | $20.00 / 1M tokens |
| Cached input | $0.50 / 1M tokens | $0.40 / 1M tokens |
| Context window | 1M | 1.05M |
| Max output | 128k | 128k |
| Released | May 2026 | Jul 9, 2026 |
| Knowledge cutoff | No data | February 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-opus-4-8 | gpt-5.6-sol |
Benchmarks side by side
Leader in bold.
| Benchmark | Claude Opus 4.8 | GPT-5.6 Sol |
|---|---|---|
| Intelligence Index | 41.8 | 47 |
| Terminal-Bench Hard | 58.3% | 65.9% |
| SciCode | 54.4% | 57.1% |
| GPQA Diamond | 92% | 94.1% |
| Humanity's Last Exam | 48.7% | 49.5% |
| IFBench (instruction following) | 62.2% | 72.7% |
| τ²-Bench (agentic tool use) | 94.4% | 85.1% |
| Long-context reasoning (AA-LCR) | 77.7% | 84% |
| MMMU-Pro (visual reasoning) | No data | 83.4% |
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 Opus 4.8 or GPT-5.6 Sol?
Choose Claude Opus 4.8 for tool use and support agents. Choose GPT-5.6 Sol for high-volume, cost-sensitive work, writing and code generation, reused prompts and documents (RAG, agents), the hardest reasoning tasks, agentic coding, reasoning over long documents and the latest release.
Which is cheaper, Claude Opus 4.8 or GPT-5.6 Sol?
GPT-5.6 Sol is 20% cheaper than Claude Opus 4.8 at the headline price ($8.00 / 1M tokens vs $10.00 / 1M tokens).
Which has the larger context window, Claude Opus 4.8 or GPT-5.6 Sol?
GPT-5.6 Sol reads more per request: 1.05M tokens against 1M.
What is the difference between Claude Opus 4.8 and GPT-5.6 Sol?
Claude Opus 4.8 is made by Anthropic and GPT-5.6 Sol by OpenAI. GPT-5.6 Sol is 20% cheaper than Claude Opus 4.8 at the headline price ($8.00 / 1M tokens vs $10.00 / 1M tokens). GPT-5.6 Sol reads more per request: 1.05M tokens against 1M. GPT-5.6 Sol is the newer model (Jul 9, 2026, against May 2026).
Which is better for coding, Claude Opus 4.8 or GPT-5.6 Sol?
GPT-5.6 Sol scores 65.9% on Terminal-Bench Hard, against 58.3% for Claude Opus 4.8.
How much do Claude Opus 4.8 and GPT-5.6 Sol cost per month?
At 20 million input and 5 million output tokens a month, Claude Opus 4.8 costs $225.00 and GPT-5.6 Sol costs $180.00, at standard rates.
Which is newer, Claude Opus 4.8 or GPT-5.6 Sol?
GPT-5.6 Sol was released on Jul 9, 2026 and Claude Opus 4.8 on May 2026.