Compare/Claude Opus 4.8 (Adaptive Reasoning, Max Effort) vs gpt-oss-20B (low)

Claude Opus 4.8 (Adaptive Reasoning, Max Effort)vsgpt-oss-20B (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-oss-20B (low)

Input
$0.06/M
Output
$0.2/M
Speed
271 tok/s
TTFT
0.46s

Winner by Category

Cheaper
gpt-oss-20B (low)
Faster (tok/s)
gpt-oss-20B (low)
Lower Latency
gpt-oss-20B (low)
Benchmarks (7-4)
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)

Pricing Comparison

MetricClaude Opus 4.8 (Adaptive Reasoning, Max Effort)gpt-oss-20B (low)
Input ($/M tokens)$6.25$0.06
Output ($/M tokens)$25$0.2
Cost for 1M input + 100K output tokens:
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)$8.75
gpt-oss-20B (low)$0.08

Speed Comparison

Output Speed (tokens/s) — higher is better
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
66 tok/s
gpt-oss-20B (low)
271 tok/s
Time to First Token (seconds) — lower is better
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)
6.54s
gpt-oss-20B (low)
0.46s

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
61.420.8
Coding Index
56.714.4
Math Index
62.3
GPQA Diamond
92.0%61.1%
MMLU-Pro
71.8%
LiveCodeBench
65.2%
AIME 2025
62.3%
MATH-500
Humanity's Last Exam
45.7%5.1%
SciCode
53.5%34.0%
IFBench
62.2%57.8%
TerminalBench
58.3%4.5%
Claude Opus 4.8 (Adaptive Reasoning, Max Effort)7 wins
4 winsgpt-oss-20B (low)

Frequently Asked Questions

Which is cheaper, Claude Opus 4.8 (Adaptive Reasoning, Max Effort) or gpt-oss-20B (low)?

gpt-oss-20B (low) is cheaper overall. Its blended price (3:1 input/output ratio) is $0.10/M tokens vs $10.94/M for Claude Opus 4.8 (Adaptive Reasoning, Max Effort).

Which model performs better on benchmarks?

Claude Opus 4.8 (Adaptive Reasoning, Max Effort) wins 7 out of 12 benchmarks compared to 4 for gpt-oss-20B (low). See the detailed benchmark chart above for per-category results.

Which is faster for real-time applications?

gpt-oss-20B (low) generates tokens faster at 271 tok/s vs 66 tok/s. However, gpt-oss-20B (low) has lower time-to-first-token (0.46s vs 6.54s).

When should I use Claude Opus 4.8 (Adaptive Reasoning, Max Effort) vs gpt-oss-20B (low)?

Choose based on your priorities: gpt-oss-20B (low) for lower cost, Claude Opus 4.8 (Adaptive Reasoning, Max Effort) for stronger benchmark performance, and gpt-oss-20B (low) for faster generation. For latency-sensitive apps, check the TTFT comparison above.