Grok-4 Fast Reasoning Benchmarks, Pricing & Rankings

Grok-4 Fast Reasoning ranks #24 of 42 tracked AI models on the AMR aggregate as of October 2026, with an aggregate score of 83.0. Its strongest dimension is GPQA Diamond at 81.5%.

Grok-4 Fast Reasoning costs $0.80 per million input tokens and $3.20 per million output tokens on the standard API. At a typical 1:3 input/output agent workload, that blends to roughly $2.60 per million tokens.

Grok-4 Fast Reasoning supports a 2M token context window and generates at a median 210 output tokens per second. That context fits roughly 1333 standard documents in a single prompt.

No — Grok-4 Fast Reasoning is a closed model available only through xAI’s official API and authorized cloud partners.

Qwen3.8 Next ranks one place higher at #23 with an AMR score of 83.6. Grok-4 Fast Reasoning still wins 0 of the tracked dimensions head-to-head — check the comparison table to see exactly which.