Compare/Grok 4.1 Fast (Reasoning) vs gpt-oss-120b (high)

Grok 4.1 Fast (Reasoning)vsgpt-oss-120b (high)

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

xAI

Grok 4.1 Fast (Reasoning)

Input
$0/M
Output
$0/M
Speed
TTFT
OpenAI

gpt-oss-120b (high)

Input
$0.15/M
Output
$0.6/M
Speed
272 tok/s
TTFT
0.52s

Winner by Category

Cheaper
Grok 4.1 Fast (Reasoning)
Faster (tok/s)
gpt-oss-120b (high)
Lower Latency
Grok 4.1 Fast (Reasoning)
Benchmarks (6-5)
Grok 4.1 Fast (Reasoning)

Pricing Comparison

MetricGrok 4.1 Fast (Reasoning)gpt-oss-120b (high)
Input ($/M tokens)$0$0.15
Output ($/M tokens)$0$0.6
Cost for 1M input + 100K output tokens:
Grok 4.1 Fast (Reasoning)$0.00
gpt-oss-120b (high)$0.21

Speed Comparison

Output Speed (tokens/s) — higher is better
Grok 4.1 Fast (Reasoning)
gpt-oss-120b (high)
272 tok/s
Time to First Token (seconds) — lower is better
Grok 4.1 Fast (Reasoning)
gpt-oss-120b (high)
0.52s

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
38.633.3
Coding Index
30.928.6
Math Index
89.393.4
GPQA Diamond
85.3%78.2%
MMLU-Pro
85.4%80.8%
LiveCodeBench
82.2%87.8%
AIME 2025
89.3%93.4%
MATH-500
Humanity's Last Exam
17.6%18.5%
SciCode
44.2%38.9%
IFBench
52.7%69.0%
TerminalBench
24.2%23.5%
Grok 4.1 Fast (Reasoning)6 wins
5 winsgpt-oss-120b (high)

Frequently Asked Questions

Which is cheaper, Grok 4.1 Fast (Reasoning) or gpt-oss-120b (high)?

Grok 4.1 Fast (Reasoning) is cheaper overall. Its blended price (3:1 input/output ratio) is $0.00/M tokens vs $0.26/M for gpt-oss-120b (high).

Which model performs better on benchmarks?

Grok 4.1 Fast (Reasoning) wins 6 out of 12 benchmarks compared to 5 for gpt-oss-120b (high). See the detailed benchmark chart above for per-category results.

Which is faster for real-time applications?

gpt-oss-120b (high) generates tokens faster at 272 tok/s vs 0 tok/s. Grok 4.1 Fast (Reasoning) also has lower time-to-first-token (0.00s vs 0.52s).

When should I use Grok 4.1 Fast (Reasoning) vs gpt-oss-120b (high)?

Choose based on your priorities: Grok 4.1 Fast (Reasoning) for lower cost, Grok 4.1 Fast (Reasoning) for stronger benchmark performance, and gpt-oss-120b (high) for faster generation. For latency-sensitive apps, check the TTFT comparison above.