Grok 4 Fast: benchmarks, price and rank
Grok 4 Fast from xAI is 107th of 123 rated AI models on Spezia's leaderboard. It costs $0.20 in, $0.50 out per million tokens.
- 107th of 123 rated models
- Rating 652
- Rated on 5 benchmarks
- Closed
- Released Aug 28, 2025
- 2 million tokens of context
Where it is strongest
Not in the top tenth on any benchmark in use.
Where it falls behind
- 97th of 98 on LMArena WebDev
- 80th of 94 on Epoch Capabilities Index
- 58th of 69 on ARC-AGI-2
Price: $0.20 in, $0.50 out per million tokens.
Its headline results
The benchmarks that count most in the rating, with its place among the models measured the same way, and where each number came from.
- BrowseComp44.9%
Questions whose answers are hidden deep on the web and take many searches and pages to track down.
47th of 56. The maker's own number, from xAI, via LLM Stats.
- Humanity's Last Exam20%
About 2,500 questions written by experts in more than a hundred fields to be as hard as they could make them, many needing a diagram or image.
53rd of 74. The maker's own number, from xAI, via LLM Stats.
- LMArena text1,407
People put a question to two anonymous models and vote for the better answer.
80th of 107. Independent result from LMArena.
- LMArena WebDev1,162
People ask two anonymous models to build the same web page or app and vote for the better one.
97th of 98. Independent result from LMArena.
- GPQA Diamond85.7%
Graduate-level questions in biology, physics and chemistry, written by PhDs so that searching the web does not give the answer away.
The maker's own number, from xAI, via LLM Stats.
- ARC-AGI-25.3%
Visual puzzles of colored grids, each with a new rule to work out from a few examples.
58th of 69. Independent result from Epoch AI.
- Epoch Capabilities Index144.3
One score built from dozens of benchmarks, set on a common scale so that models tested on different benchmarks can still be compared.
80th of 94. Independent result from Epoch AI.
1 more results in its full profile.
Every result with its source, what it costs per task, what jumped with its release, side by side with any other model, and answers to your questions about when to use it.
Models ranked near it
How the rating works, and every benchmark it uses: the model leaderboard.