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

Claude Opus 4.8 (Adaptive Reasoning, Max Effort)vsGPT-5.5 (low)

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

Anthropic

Claude Opus 4.8 (Adaptive Reasoning, Max Effort)

Input
$6.25/M
Output
$25/M
Speed
66 tok/s
TTFT
6.54s
OpenAI

GPT-5.5 (low)

Input
$5/M
Output
$30/M
Speed
60 tok/s
TTFT
1.62s

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
GPT-5.5 (low)
Benchmarks (6-1)
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)

Pricing Comparison

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

Speed Comparison

Output Speed (tokens/s) — higher is better
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
66 tok/s
GPT-5.5 (low)
60 tok/s
Time to First Token (seconds) — lower is better
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
6.54s
GPT-5.5 (low)
1.62s

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
61.450.8
Coding Index
56.752.1
Math Index
GPQA Diamond
92.0%91.0%
MMLU-Pro
LiveCodeBench
AIME 2025
MATH-500
Humanity's Last Exam
45.7%31.0%
SciCode
53.5%51.6%
IFBench
62.2%64.4%
TerminalBench
58.3%52.3%
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)6 wins
1 winsGPT-5.5 (low)

Frequently Asked Questions

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

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 (low).

Which model performs better on benchmarks?

Claude Opus 4.8 (Adaptive Reasoning, Max Effort) wins 6 out of 12 benchmarks compared to 1 for GPT-5.5 (low). 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 66 tok/s vs 60 tok/s. However, GPT-5.5 (low) has lower time-to-first-token (1.62s vs 6.54s).

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

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 Claude Opus 4.8 (Adaptive Reasoning, Max Effort) for faster generation. For latency-sensitive apps, check the TTFT comparison above.