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

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

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

OpenAI

GPT-5.5 (medium)

Input
$5/M
Output
$30/M
Speed
67 tok/s
TTFT
5.29s
Anthropic

Claude Opus 4.8 (Adaptive Reasoning, Max Effort)

Input
$5/M
Output
$25/M
Speed
61 tok/s
TTFT
25.40s

Winner by Category

Cheaper
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
Faster (tok/s)
GPT-5.5 (medium)
Lower Latency
GPT-5.5 (medium)
Benchmarks (2-4)
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)

Pricing Comparison

MetricGPT-5.5 (medium)Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
Input ($/M tokens)$5$5
Output ($/M tokens)$30$25
Cost for 1M input + 100K output tokens:
GPT-5.5 (medium)$8.00
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)$7.50

Speed Comparison

Output Speed (tokens/s) — higher is better
GPT-5.5 (medium)
67 tok/s
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
61 tok/s
Time to First Token (seconds) — lower is better
GPT-5.5 (medium)
5.29s
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
25.40s

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
50.455.7
Coding Index
71.574.3
Math Index
GPQA Diamond
92.6%92.0%
MMLU-Pro
LiveCodeBench
AIME 2025
MATH-500
Humanity's Last Exam
40.6%45.7%
SciCode
53.5%53.5%
IFBench
71.0%62.2%
TerminalBench
57.6%58.3%
GPT-5.5 (medium)2 wins
4 winsClaude Opus 4.8 (Adaptive Reasoning, Max Effort)

Frequently Asked Questions

Which is cheaper, GPT-5.5 (medium) 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 $10.00/M tokens vs $11.25/M for GPT-5.5 (medium).

Which model performs better on benchmarks?

Claude Opus 4.8 (Adaptive Reasoning, Max Effort) wins 4 out of 12 benchmarks compared to 2 for GPT-5.5 (medium). See the detailed benchmark chart above for per-category results.

Which is faster for real-time applications?

GPT-5.5 (medium) generates tokens faster at 67 tok/s vs 61 tok/s. GPT-5.5 (medium) also has lower time-to-first-token (5.29s vs 25.40s).

When should I use GPT-5.5 (medium) 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, Claude Opus 4.8 (Adaptive Reasoning, Max Effort) for stronger benchmark performance, and GPT-5.5 (medium) for faster generation. For latency-sensitive apps, check the TTFT comparison above.