xAI

Grok 4 Fast

Type
language model
Context
2,000K tokens
Max output
64K
Released
19 September 2025
Knowledge cutoff
January 2025
API string
x-ai/grok-4-fast

Prices by provider

Provider Input, $ per 1M Output, $ per 1M In our data since
Requesty $0.2 $0.5 31 Jul 2026
ZenMux $0.2 $0.5 31 Jul 2026
OCI Generative AI $5 $25 31 Jul 2026

Only the base tier and only per-token prices are shown. Batch, discounted and cached rates, as well as prices per image or per second of video, do not go into this table: they cannot stand in the same column as a price per million tokens.

The date in the last column is the day this price first entered our collection. The price may well be older: before that day we simply were not recording it. It has not changed since — otherwise a new row with a new date would stand in its place.

Measurement results

Task set Result Run conditions Measured by
Fiction.LiveBench — holding a long context 94.4 % Fiction.live leaderboard
ARC-AGI — generalising to unseen patterns 48.5 % · with a tuned harness
WeirdML — unusual machine learning tasks 42.86 % WeirdML Leaderboard
Cybench — cybersecurity tasks 30 % · with a tuned harness Grok 4 Fast Model Card self-reported
ARC-AGI-2 5.28 %