Models

Grok 4.1 Fast (reasoning) vs Grok 4.5

Compare Grok 4.1 Fast (reasoning) from Grok and Grok 4.5 from Grok on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the AIHubMix API.

GrokGrok 4.1 Fast (reasoning)GrokGrok 4.5
Grok logo
Grok 4.1 Fast (reasoning)
Grok · text, image → text

Grok 4.1 is a new conversational model with significant improvements in real-world usability, delivering exceptional performance in creative, emotional, and collaborative interactions. It is more perceptive to nuanced user intent, more engaging to converse with, and more coherent in personality, while fully preserving its core intelligence and reliability. Built on large-scale reinforcement learning infrastructure, the model is optimized for style, personality, helpfulness, and alignment, and leverages frontier agentic reasoning models as reward evaluators to autonomously assess and iterate on responses at scale, significantly enhancing overall interaction quality.

Input$0.20 /M
Output$0.50 /M
Grok logo
Grok 4.5
Grok · text, image → text

Grok 4.5 was trained on datasets spanning knowledge in coding, science, engineering, and math. With both intelligent and efficient reasoning, Grok 4.5 excels at real engineering tasks and exceeds comparable leading models at these tasks.

Input$2.00 /M
Output$6.00 /M

Pricing & Specifications

Prices are per million tokens. Time to First Token and throughput are rolling averages measured on AIHubMix.

Grok 4.1 Fast (reasoning)
Grok 4.5
Input /M
$0.20
$2.00
Output /M
$0.50
$6.00
Cache read /M
$0.05
$0.50
Context length
2,000,000
500,000
Max output
2,000,000
500,000
Time to First Token
2.8 s
2.6 s
Throughput
75.0 tok/s
30.2 tok/s
Modalities
textimage
textimage
Supported Parameters
thinkingtoolsfunction callingstructured outputs
thinkingtoolsfunction callingstructured outputslong context
API Formats
Released
-
July 2026

Promotional prices show the discounted rate; see each model page for promotion windows.

Activity Past 30 Days

Daily traffic served through AIHubMix — how demand for each model is trending.

grok-4-1-fast-reasoninggrok-4.5

Tokens / day

-

Requests / day

-

Performance Past 3 Days

Measured on real AIHubMix traffic, hourly buckets. Gaps mean no traffic in that hour.

grok-4-1-fast-reasoninggrok-4.5

Throughput (tok/s)

-

TTFT (s)

-

Uptime (%)

-

LMArena Benchmarks

LMArena ratings by capability (Bradley-Terry, commonly called Elo). Higher is better.

Text
grok-4-1-fast-reasoninggrok-4.5
13801420146015001540
Overall
14311470
Coding
14611523
Math
14181478
Hard prompts
14411495
Instruction following
14021466
Multi-turn
14151477
Creative writing
14141449
Longer query
14231485
Chinese
14621511
English
14411475
Vision
grok-4-1-fast-reasoninggrok-4.5
1140120012601320
Overall
11951282
OCR
11921295
Diagram
12151321
Homework
11711328
WebDev Arena
grok-4-1-fast-reasoninggrok-4.5
1200132014401560
Overall
12401556
React
12221559
HTML
12521577
Gaming
12401586
Simulations
12401598
Data analytics
12351522

Source: LMArena (arena.ai) leaderboard, imported by AIHubMix. Models without published ratings are omitted per chart.

Cost calculator

Estimate your monthly bill for the same workload on each model.

Grok 4.1 Fast (reasoning)
$19.50 /mo
Grok 4.5
$210 /mo

Monthly = daily × 30. Discounted rates applied where a promotion is active.

FAQ

Which is cheaper: Grok 4.1 Fast (reasoning), Grok 4.5?

Grok 4.1 Fast (reasoning): $0.50/M output tokens; Grok 4.5: $6.00/M. Use the cost calculator above to estimate your own workload.

How do their coding arena scores compare?

Grok 4.5: 1523; Grok 4.1 Fast (reasoning): 1461 (LMArena coding leaderboard).

Which responds faster?

Grok 4.5: 2.6s time to first token measured on AIHubMix; see the live performance charts above for how each model behaves across the day.

How large is each context window?

Grok 4.1 Fast (reasoning) accepts 2,000,000 and Grok 4.5 accepts 500,000 input tokens. Maximum output per request is 2,000,000 tokens on Grok 4.1 Fast (reasoning) and 500,000 tokens on Grok 4.5.

Which one generates tokens faster?

Grok 4.1 Fast (reasoning) at 75.0 tok/s and Grok 4.5 at 30.2 tok/s, measured as output throughput on AIHubMix — a separate metric from time to first token.

What inputs and capabilities does each model support?

Grok 4.1 Fast (reasoning) accepts text and image input and supports thinking, tool calling, function calling and structured outputs; Grok 4.5 accepts text and image input and supports thinking, tool calling, function calling, structured outputs and long context.

Can I call Grok 4.1 Fast (reasoning) and Grok 4.5 with the same API key?

Yes. AIHubMix serves every model on this page behind one OpenAI-compatible endpoint, so switching between them is a one-line change to the model field — no second account, key or SDK.

Popular comparisons

Related model match-ups readers also look at.