Compare/GPT-5.5 (xhigh) vs Claude Opus 4.8 (Adaptive Reasoning, Max Effort)

GPT-5.5 (xhigh)vsClaude Opus 4.8 (Adaptive Reasoning, Max Effort)

Side-by-side comparison of pricing, 12 benchmarks, and generation speed.

OpenAI

GPT-5.5 (xhigh)

Input
$5/M
Output
$30/M
Speed
55 tok/s
TTFT
78.70s
Anthropic

Claude Opus 4.8 (Adaptive Reasoning, Max Effort)

Input
$6.25/M
Output
$25/M
Speed
60 tok/s
TTFT
26.26s

Winner by Category

Cheaper
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
Faster (tok/s)
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
Lower Latency
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
Benchmarks (5-2)
GPT-5.5 (xhigh)

Pricing Comparison

MetricGPT-5.5 (xhigh)Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
Input ($/M tokens)$5$6.25
Output ($/M tokens)$30$25
Cost for 1M input + 100K output tokens:
GPT-5.5 (xhigh)$8.00
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)$8.75

Speed Comparison

Output Speed (tokens/s) — higher is better
GPT-5.5 (xhigh)
55 tok/s
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
60 tok/s
Time to First Token (seconds) — lower is better
GPT-5.5 (xhigh)
78.70s
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
26.26s

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
60.261.4
Coding Index
59.156.7
Math Index
GPQA Diamond
93.5%92.0%
MMLU-Pro
LiveCodeBench
AIME 2025
MATH-500
Humanity's Last Exam
44.3%45.7%
SciCode
56.1%53.5%
IFBench
75.9%62.2%
TerminalBench
60.6%58.3%
GPT-5.5 (xhigh)5 wins
2 winsClaude Opus 4.8 (Adaptive Reasoning, Max Effort)

Frequently Asked Questions

Which is cheaper, GPT-5.5 (xhigh) or Claude Opus 4.8 (Adaptive Reasoning, Max Effort)?

Claude Opus 4.8 (Adaptive Reasoning, Max Effort) is cheaper overall. Its blended price (3:1 input/output ratio) is $10.94/M tokens vs $11.25/M for GPT-5.5 (xhigh).

Which model performs better on benchmarks?

GPT-5.5 (xhigh) wins 5 out of 12 benchmarks compared to 2 for Claude Opus 4.8 (Adaptive Reasoning, Max Effort). See the detailed benchmark chart above for per-category results.

Which is faster for real-time applications?

Claude Opus 4.8 (Adaptive Reasoning, Max Effort) generates tokens faster at 60 tok/s vs 55 tok/s. However, Claude Opus 4.8 (Adaptive Reasoning, Max Effort) has lower time-to-first-token (26.26s vs 78.70s).

When should I use GPT-5.5 (xhigh) vs Claude Opus 4.8 (Adaptive Reasoning, Max Effort)?

Choose based on your priorities: Claude Opus 4.8 (Adaptive Reasoning, Max Effort) for lower cost, GPT-5.5 (xhigh) for stronger benchmark performance, and Claude Opus 4.8 (Adaptive Reasoning, Max Effort) for faster generation. For latency-sensitive apps, check the TTFT comparison above.