AI Model Comparison

Claude Opus 4.8 vs GPT-5.5 (xhigh)

Compare Claude Opus 4.8 (Adaptive Reasoning, Max Effort) vs GPT-5.5 (xhigh) with benchmark results, speed, pricing, and practical workflow guidance.

Best For Claude Opus 4.8 (Adaptive Reasoning, Max Effort)

  • Interactive reasoning tasks
  • Low-latency application needs
  • Cost-sensitive high-volume output

Best For GPT-5.5 (xhigh)

  • Complex coding projects
  • Strict instruction following
  • High-speed batch processing

Claude Opus 4.8 and GPT-5.5 (xhigh) represent the pinnacle of current AI development. While Claude offers superior reasoning efficiency, GPT-5.5 excels in coding performance and instruction following, presenting a clear choice based on specific project requirements.

Quick Take

Released in mid-2026, Claude Opus 4.8 (Anthropic) and GPT-5.5 (xhigh) (OpenAI) are leading-edge models. Claude Opus 4.8 focuses on adaptive reasoning, while GPT-5.5 emphasizes raw coding capability and instruction adherence.

Benchmark Read

Performance metrics highlight distinct specializations:

  • Intelligence: Claude Opus 4.8 leads with an index of 61.4 compared to GPT-5.5's 60.2.
  • Coding: GPT-5.5 holds the edge with a 59.1 coding index versus Claude’s 56.7.
  • Instruction Following: GPT-5.5 significantly outperforms Claude on IFBench (0.758 vs 0.622) and LCR (0.743 vs 0.676).
  • Specialized Tasks: Claude Opus 4.8 shows strength in TAU2 (0.944), while GPT-5.5 performs better in TerminalBench Hard (0.606) and SciCode (0.561).

Cost and Speed

Efficiency profiles differ significantly between the two providers:

  • Pricing: Claude Opus 4.8 has a blended cost of $10.94/1M tokens, slightly cheaper than GPT-5.5’s $11.25/1M. Claude’s output is cheaper ($25.00 vs $30.00), though OpenAI offers a lower input price ($5.00 vs $6.25).
  • Latency: Claude Opus 4.8 is vastly superior in responsiveness, with a time-to-first-token of 10.572s compared to GPT-5.5’s 55.023s. However, GPT-5.5 offers a higher output speed of 77.617 tok/s against Claude’s 65.316 tok/s.

Best Fit

Claude Opus 4.8 is optimized for users requiring fast, interactive reasoning and lower overall blended costs. GPT-5.5 is the preferred choice for developers prioritizing coding accuracy and complex, multi-step instruction following.

Benchmark table

Side-by-side scores, speed, and pricing for the selected models.

Metric Anthropic Claude Opus 4.8 (Adaptive Reasoning, Max Effort) OpenAI GPT-5.5 (xhigh)
Index Scores
Intelligence Index 61.4 60.2
Coding Index 56.7 59.1
Math Index--
Benchmark Scores
GPQA 92.0 93.5
SciCode 53.5 56.1
IFBench 62.2 75.9
HLE 45.7 44.3
LCR 67.7 74.3
TAU2 94.4 93.9
TerminalBench Hard 58.3 60.6

Verdict

Choose Claude Opus 4.8 if your workflow demands rapid response times and high-level reasoning, as its significantly lower time-to-first-token makes it ideal for interactive applications. Conversely, select GPT-5.5 (xhigh) for complex coding tasks and instruction-heavy workflows where its higher coding index and superior IFBench scores provide a distinct advantage, despite the slower initial response latency.

Comments (0)

No comments yet

Be the first to share your thoughts!