Model profile

xAI

Grok 4 Fast (Reasoning)

Grok 4 Fast (Reasoning) is a budget text-first model from xAI with a balanced runtime profile, unknown context posture, and the clearest fit around coding / agent workflows.

Best for: Coding / Agent workflowsBalanced latencyUnknown contextBudget pricing

Intelligence: 35.1
Coding: 0.832
Context: N/A
Input Price: $0.20

Decision snapshot

Grok 4 Fast (Reasoning) currently reads as a budget text-first option with unknown context and a balanced runtime profile.

Overall profile: Use-case specific
Best for: Coding / Agent workflows
Latency tier: Balanced
Price tier: Budget

Source coverage

OpenRouter

Compare this model See leaderboard

Decision Strip

Decision rail before the raw tables

Core buy-side signals stay in one pass. The rest of the page expands only after intelligence, speed, context, and price are clear.

Intelligence

35.1

General reasoning and benchmark headroom.

Limited

Speed

162 tok/s

TTFT 3.06s

Competitive

Context

N/A

How much prompt and task state can stay in view.

Limited

Price

$0.20

$0.50 output / 1M

Efficient

Editorial Profile

Grok 4 Fast (Reasoning) in one narrative

Positioning, tradeoffs, and fit are consolidated into one read instead of repeating the same story across separate cards.

Use-case specificCoding score 40Math score 36

The Grok 4 Fast (Reasoning) AI model by xAI.

Identity

xAI text-first profile

Positioning

Coding / Agent workflows with unknown context and balanced runtime.

Cost posture

Efficient spend profile. More comfortable for sustained prompt volume if the capability fit is right.

Strengths

The available source data suggests a balanced profile rather than one dominant edge.

Tradeoffs

Budget-friendly input pricing is a strength, but raw capability may vary by workload.
Latency is balanced rather than ultra-fast, which is fine for most workflows but not the snappiest tier.
Current metadata points to a text-first profile rather than a broad multimodal one.

Best fit

Focused chat, retrieval-augmented flows, and narrower production tasks.

Compare Next

Similar profiles worth opening next

xAI

Grok 3 mini Reasoning (high)

Intelligence: 32.1
Context: N/A
Input Price: $0.30

Compare Open profile

xAI

Grok 4.1 Fast (Non-reasoning)

Intelligence: 23.6
Context: N/A
Input Price: $0.20

Compare Open profile

xAI

Grok 3 Reasoning Beta

Intelligence: 21.6
Context: N/A
Input Price: $0.00

Compare Open profile

Benchmarks

Grouped by job-to-be-done

Only benchmark categories with actual signal are shown. Secondary values stay as simple definitions instead of nested micro-cards.

General intelligence

Broad reasoning, knowledge depth, and flagship benchmark posture.

Intelligence Index: 35.1

MMLU Pro: 85.0%
GPQA: 84.7%

Coding

Software implementation, debugging quality, and coding benchmark signal.

LiveCodeBench: 0.832

Extra benchmark cuts are not available for this category yet.

Specs & Pricing

Technical snapshot and cost posture

Specs stay neutral, pricing gets emphasis through values rather than extra containers. Raw provider internals remain in metadata at the end.

Technical snapshot

Context Window: N/A
Vision: Text-first

Price architecture

Input: per 1M input tokens
Output: per 1M output tokens
Blended: AA 3:1 mix

This model is relatively efficient on price. It is the easier fit when sustained prompt volume matters.