Models

Gemini 3.8 Flash vs Grok 4.5

Compare Gemini 3.8 Flash from Google 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.

GoogleGemini 3.8 FlashGrokGrok 4.5
Google logo
Gemini 3.8 Flash
Google · text, image, audio, video → text

Gemini 3.8 Flash is Google's most intelligent Flash-series model, designed for long-running software engineering tasks, autonomous agents, and complex enterprise workflows, while retaining the Flash series' fast responsiveness and cost-effectiveness.

Input$0.75 /M
Output$3.75 /M
Cache read$0.075 /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 /M
Output$6 /M
Cache read$0.5 /M

Pricing & Specifications

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

Gemini 3.8 Flash
Grok 4.5
Input /M
$0.75
$2
Output /M
$3.75
$6
Cache read /M
$0.075
$0.5
Context length
1,048,576
500,000
Max output
65,536
500,000
Time to First Token
5.1 s
2.8 s
Throughput
54.9 tok/s
31.5 tok/s
Modalities
textimageaudiovideo
textimage
Supported Parameters
thinkingtoolsfunction callingstructured outputsweblong context
thinkingtoolsfunction callingstructured outputslong context
API Formats
chat_completions · gemini_api · claude_api
Released
September 2, 2026
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.

gemini-3.8-flashgrok-4.5

Tokens / day

-

Requests / day

-

Performance Past 3 Days

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

gemini-3.8-flashgrok-4.5

Throughput (tok/s)

-

TTFT (s)

-

Uptime (%)

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LMArena Benchmarks

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

Text
gemini-3.8-flashgrok-4.5
14201460150015401580
Overall
14711494
Coding
15231537
Math
14791501
Hard prompts
14951518
Instruction following
14661491
Multi-turn
14761516
Creative writing
14511495
Longer query
14871510
Chinese
15121547
English
14761504
WebDev Arena
gemini-3.8-flashgrok-4.5
1500154015801620
Overall
15561567
React
15571559
HTML
15711602
Gaming
15891615
Simulations
15851592
Data analytics
15211549

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.

Gemini 3.8 Flash
$101 /mo
Grok 4.5
$210 /mo

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

FAQ

Which is cheaper: Gemini 3.8 Flash, Grok 4.5?

Gemini 3.8 Flash: $3.75/M output tokens; Grok 4.5: $6/M. Use the cost calculator above to estimate your own workload.

How do their coding arena scores compare?

Gemini 3.8 Flash: 1537; Grok 4.5: 1523 (LMArena coding leaderboard).

Which responds faster?

Grok 4.5: 2.8s 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?

Gemini 3.8 Flash accepts 1,048,576 and Grok 4.5 accepts 500,000 input tokens. Maximum output per request is 65,536 tokens on Gemini 3.8 Flash and 500,000 tokens on Grok 4.5.

Which one generates tokens faster?

Gemini 3.8 Flash at 54.9 tok/s and Grok 4.5 at 31.5 tok/s, measured as output throughput on AIHubMix — a separate metric from time to first token.

What inputs and capabilities does each model support?

Gemini 3.8 Flash accepts text, image, audio and video input and supports thinking, tool calling, function calling, structured outputs, web search and long context; Grok 4.5 accepts text and image input and supports thinking, tool calling, function calling, structured outputs and long context.

Can I call Gemini 3.8 Flash 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.

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