gpt-oss-120b vs grok-4-1-fast-reasoning

Capability for the money

Not the same tier: gpt-oss-120b leads grok-4-1-fast-reasoning by 16.3 points on following instructions (IFBench), for 1.6× the price. They are level on coding (LiveCodeBench), tool use (τ²-bench) and hard reasoning (GPQA Diamond), so the premium only pays off on following instructions work.

1. Following instructions

   extraction, classification, sticking to a format

   IFBench
   gpt-oss-120b69.0%

   grok-4-1-fast-reasoning52.7%

   gpt-oss-120b +16.3

2. Coding

   writing and fixing code

   LiveCodeBench
   gpt-oss-120b87.8%

   grok-4-1-fast-reasoning82.2%

   gpt-oss-120b +5.6

3. Tool use

   multi-step agent work against real tools

   τ²-bench
   gpt-oss-120b65.8%

   grok-4-1-fast-reasoning93.3%

   grok-4-1-fast-reasoning +27.5

4. Hard reasoning

   graduate-level science and multi-step analysis

   GPQA Diamond
   gpt-oss-120b78.2%

   grok-4-1-fast-reasoning85.3%

   grok-4-1-fast-reasoning +7.1

Averaged over the benchmarks both models sat, grok-4-1-fast-reasoning returns 285.0 points of pass rate per dollar of blended price against 167.1 — the ratio that decides whether the dearer model earns its rate.

Each figure is a pass rate: the share of that test set the model answered correctly, measured by a third party rather than self-reported by the lab. Rows are different tests of different difficulty, so compare a model against the other model, not one row against the next. And a benchmark is not your workload — it narrows the shortlist, it does not pick for you.