Claude Opus 4.5 vs GPT-5.6 Sol: price, context and capabilities

Choose GPT-5.6 Sol for high-volume, cost-sensitive work, writing and code generation, reused prompts and documents (RAG, agents), very long inputs, agentic coding, reasoning over long documents and the latest release; on the other points the two are level or the data is missing.

In short

  • GPT-5.6 Sol is 20% cheaper than Claude Opus 4.5 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 200k.
  • GPT-5.6 Sol is the newer model (Jul 9, 2026, against November 2025).

Open in the full comparison table

What a month costsAt 20 million input and 5 million output tokens a month.
  1. Claude Opus 4.5Anthropic$225
  2. GPT-5.6 SolOpenAI$180

Try your own volumes in the calculator

Which should you choose?

Each answer below comes straight from the published prices, specifications and independent benchmark results.

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).

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 4.5. 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 4.5.

Very long inputs

Choose GPT-5.6 Sol

GPT-5.6 Sol reads up to 1.05M tokens per request, against 200k for Claude Opus 4.5.

Agentic coding

Choose GPT-5.6 Sol

GPT-5.6 Sol scores 65.9% on Terminal-Bench Hard, against 40.9% for Claude Opus 4.5.

Tool use and support agents

Either one

They are practically level on τ²-Bench (agentic tool use) (86.3% and 85.1%).

Reasoning over long documents

Choose GPT-5.6 Sol

GPT-5.6 Sol scores 84% on Long-context reasoning (AA-LCR), against 70.7% for Claude Opus 4.5.

Latest release

Choose GPT-5.6 Sol

GPT-5.6 Sol is the newer release (Jul 9, 2026, against November 2025 for Claude Opus 4.5).

Monthly cost at three volumes

VolumeClaude Opus 4.5GPT-5.6 SolDifference
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 4.5GPT-5.6 Sol
ProviderAnthropicOpenAI
CategoryLanguage modelsLanguage models
StatusLegacyGenerally 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 window200k1.05M
Max output64k128k
ReleasedNovember 2025Jul 9, 2026
Knowledge cutoffNo dataFebruary 2026
LicenceProprietaryProprietary
CapabilitiesVision, Reasoning, Tool calling, Structured output, Prompt caching, Batch APIVision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API
API model idclaude-opus-4-5-20251101gpt-5.6-sol

Benchmarks side by side

Leader in bold.

BenchmarkClaude Opus 4.5GPT-5.6 Sol
Terminal-Bench Hard 40.9% 65.9%
GPQA Diamond 81% 94.1%
Humanity's Last Exam 13.2% 49.5%
IFBench (instruction following) 43% 72.7%
τ²-Bench (agentic tool use) 86.3% 85.1%
MMMU-Pro (visual reasoning) 71.2% 83.4%
Long-context reasoning (AA-LCR) 70.7% 84%
Intelligence Index No data 47
SciCode No data 57.1%

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 4.5 or GPT-5.6 Sol?

Choose GPT-5.6 Sol for high-volume, cost-sensitive work, writing and code generation, reused prompts and documents (RAG, agents), very long inputs, agentic coding, reasoning over long documents and the latest release; on the other points the two are level or the data is missing.

Which is cheaper, Claude Opus 4.5 or GPT-5.6 Sol?

GPT-5.6 Sol is 20% cheaper than Claude Opus 4.5 at the headline price ($8.00 / 1M tokens vs $10.00 / 1M tokens).

Which has the larger context window, Claude Opus 4.5 or GPT-5.6 Sol?

GPT-5.6 Sol reads more per request: 1.05M tokens against 200k.

What is the difference between Claude Opus 4.5 and GPT-5.6 Sol?

Claude Opus 4.5 is made by Anthropic and GPT-5.6 Sol by OpenAI. GPT-5.6 Sol is 20% cheaper than Claude Opus 4.5 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 200k. GPT-5.6 Sol is the newer model (Jul 9, 2026, against November 2025).

Which is better for coding, Claude Opus 4.5 or GPT-5.6 Sol?

GPT-5.6 Sol scores 65.9% on Terminal-Bench Hard, against 40.9% for Claude Opus 4.5.

How much do Claude Opus 4.5 and GPT-5.6 Sol cost per month?

At 20 million input and 5 million output tokens a month, Claude Opus 4.5 costs $225.00 and GPT-5.6 Sol costs $180.00, at standard rates.

Which is newer, Claude Opus 4.5 or GPT-5.6 Sol?

GPT-5.6 Sol was released on Jul 9, 2026 and Claude Opus 4.5 on November 2025.