grok-4-fast-reasoning

Name: grok-4-fast-reasoning
Price: 0.2 USD
Availability: InStock
Author: xai

xAI · grok-4-fast-reasoning

Fast Grok model for responsive chat, reasoning, and tool-assisted work

Specification

most-agreed values

Context

Max output

30K

Released

2025-12-18

Knowledge cutoff

2025-06

Retires

2026-05-01

Open weights

Input

text, image

Output

text

US dollars per million tokens · most-agreed

Input

$0.20

Output

$0.50

Cache read

$0.05

Host	In $/M	Out $/M	Cache rd	Cache wr	Context	Output	Retires
jiekou	$0.18	$0.45	—	—	2M	2M	—
302ai	$0.20	$0.50	—	—	2M	30K	—
azure_ai	$0.20	$0.50	—	—	—	—	2026-05-01
helicone	$0.20	$0.50	$0.05	—	2M	2M	—
poe	$0.20	$0.50	$0.05	—	2M	128K	—
qiniu-ai · x-ai	—	—	—	—	2M	2M	—

append-only observations · a listing writes a row only when its price moves

Date	Host	Field	$/M
2026-09-02	azure_ai	Input	$0.20
2026-09-26	azure_ai	Input	$0.20
2026-09-02	azure_ai	Output	$0.50
2026-09-26	azure_ai	Output	$0.50