Gemini 3.1 Flash-Lite vs Grok 4.1 Fast
Pricing & Specs

Google (Gemini) vs xAI, side by side from a live registry. Specs below, then benchmark both on your own task.

$1.5
Gemini 3.1 Flash-Lite output / 1M
$0.5
Grok 4.1 Fast output / 1M
1.04858M / 2M
context windows

TL;DR: On a typical task (1K input + 500 output tokens), Grok 4.1 Fast is about 2.2x cheaper than Gemini 3.1 Flash-Lite. But per-token price is not cost per result: a cheaper model that needs more tokens, retries, or hand-holding can end up more expensive on your workload. The specs below are facts; which one is better at YOUR task is measurable, not guessable.

API Pricing: Gemini 3.1 Flash-Lite vs Grok 4.1 Fast

TokensGemini 3.1 Flash-LiteGrok 4.1 Fast
Input$0.25 / 1M$0.2 / 1M
Output$1.5 / 1M$0.5 / 1M
Cached input$0.01 / 1M$0.05 / 1M

What that means in practice (1K input + 500 output tokens)

1x One typical task: $0.0010 on Gemini 3.1 Flash-Lite vs $0.0004 on Grok 4.1 Fast
1K 1,000 runs: $1.00 vs $0.45
💡 Real cost depends on how verbose each model is on YOUR prompts. Benchmark to measure actual tokens, not estimates.

Specs Compared

SpecGemini 3.1 Flash-LiteGrok 4.1 Fast
Context window1.04858M tokens2M tokens
Max output tokens65.536K tokens-
Input modalitiestext, image, audio, video, PDFtext, image
Knowledge cutoffJanuary 2025-
Latency (measured)-~1.4s median response
Reasoning modelNoYes
Tool / function callingYesYes
JSON modeYesYes
Prompt cachingYesYes

When to Choose Which

High volume on a budget: start with Grok 4.1 Fast; only pay for Gemini 3.1 Flash-Lite if the benchmark shows a quality gap that matters.
Long documents or big codebases: Grok 4.1 Fast has the larger context window (2M vs 1.04858M tokens).
Multi-step reasoning tasks: Grok 4.1 Fast is a reasoning model; expect better step-by-step work at the cost of more output tokens.
Everything else: the honest answer is to benchmark both on your actual task. Quality differences are task-specific and shift with every release.

FAQ

Which is cheaper, Gemini 3.1 Flash-Lite or Grok 4.1 Fast?

Gemini 3.1 Flash-Lite costs $0.25/$1.5 per 1M input/output tokens; Grok 4.1 Fast costs $0.2/$0.5. On a typical task (1K input + 500 output tokens), Grok 4.1 Fast is about 2.2x cheaper than Gemini 3.1 Flash-Lite.

Which has the bigger context window, Gemini 3.1 Flash-Lite or Grok 4.1 Fast?

Gemini 3.1 Flash-Lite has a 1.04858M-token context window; Grok 4.1 Fast has 2M tokens.

Is Gemini 3.1 Flash-Lite better than Grok 4.1 Fast?

It depends on the task. Generic leaderboards won't tell you which one wins on YOUR workload. OpenMark lets you benchmark Gemini 3.1 Flash-Lite and Grok 4.1 Fast head to head on your own task with real API calls, no API keys needed, free tier available.

Gemini 3.1 Flash-Lite or Grok 4.1 Fast for YOUR Task?

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