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LLM ComparisonClaude 4 OpusGPT-5.5

Claude 4 Opus vs GPT-5.5

Compare Claude 4 Opus and GPT-5.5. Build AI products powered by either model on Appaca.

Model Comparison

FeatureClaude 4 OpusGPT-5.5
ProviderAnthropicOpenAI
Model Typetexttext
Context Window200,000 tokens1,000,000 tokens
Input Cost
$15.00/ 1M tokens
$5.00/ 1M tokens
Output Cost
$75.00/ 1M tokens
$30.00/ 1M tokens

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Strengths & Best Use Cases

Claude 4 Opus

Anthropic
  • Highest capability in the family: described as “our most powerful model yet” by Anthropic.
  • Exceptional at long-running tasks requiring thousands of steps and sustained focus (e.g., continuous codebase work for hours).
  • Excellent performance on benchmarks: e.g., SWE-bench 72.5 % and Terminal-bench 43.2 %.
  • Designed for complex agentic workflows, deep reasoning, tool use, and large context windows.
  • Placed under a higher safety classification (ASL-3) due to its frontier capability and risk profile.

GPT-5.5

OpenAI

1. Strongest Agentic Coding Model

  • State-of-the-art on Terminal-Bench 2.0 (82.7%), Expert-SWE (73.1%), and SWE-Bench Pro (58.6%), outperforming GPT-5.4 on complex coding tasks.
  • Holds context across large systems, reasons through ambiguous failures, and carries changes through surrounding codebases with fewer tokens.

2. Higher Intelligence at GPT-5.4 Latency

  • Co-designed, trained, and served on NVIDIA GB200/GB300 NVL72 systems to match GPT-5.4 per-token latency while performing at a significantly higher level.
  • Uses fewer tokens to complete the same tasks, making it more efficient as well as more capable.

3. Powerful for Knowledge Work & Computer Use

  • Scores 84.9% on GDPval (44 occupations) and 78.7% on OSWorld-Verified for autonomous computer operation.
  • Excels at generating documents, spreadsheets, and reports; naturally moves across finding information, using tools, and checking output.

4. Scientific Research Co-Scientist

  • Leading performance on GeneBench, BixBench, and FrontierMath; helped discover a new proof about Ramsey numbers verified in Lean.
  • Strong enough to meaningfully accelerate progress at the frontiers of biomedical and mathematical research.