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

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

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

OpenAI

GPT-5.5 (low)

Input
$5/M
Output
$30/M
Speed
53 tok/s
TTFT
1.81s
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
GPT-5.5 (low)
Benchmarks (1-6)
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)

Pricing Comparison

MetricGPT-5.5 (low)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 (low)$8.00
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)$8.75

Speed Comparison

Output Speed (tokens/s) — higher is better
GPT-5.5 (low)
53 tok/s
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
60 tok/s
Time to First Token (seconds) — lower is better
GPT-5.5 (low)
1.81s
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
26.26s

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
50.861.4
Coding Index
52.156.7
Math Index
GPQA Diamond
91.0%92.0%
MMLU-Pro
LiveCodeBench
AIME 2025
MATH-500
Humanity's Last Exam
31.0%45.7%
SciCode
51.6%53.5%
IFBench
64.4%62.2%
TerminalBench
52.3%58.3%
GPT-5.5 (low)1 wins
6 winsClaude Opus 4.8 (Adaptive Reasoning, Max Effort)

Frequently Asked Questions

Which is cheaper, GPT-5.5 (low) 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 (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 60 tok/s vs 53 tok/s. GPT-5.5 (low) also has lower time-to-first-token (1.81s vs 26.26s).

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