Gemini 2.5 Flash vs Grok 3

Gemini 2.5 Flash vs Grok 3: Gemini 2.5 Flash is cheaper by 90% on average. Gemini 2.5 Flash from Google Vertex AI (1,048,576-token context, reasoning, tool calls) vs. Grok 3 from xAI (131,072-token context, tool calls). Use Agent Command Center to A/B both in shadow mode and pick the winner per workload.

Side-by-side cost

Live workload comparison

Same workload run through both models. The cheaper one is highlighted.

Input tokens / request3,000

01,048,576

Output tokens / request400

0131,072

Requests / day5,000

01,000,000

Gemini 2.5 FlashCheaper

Google Vertex AI

$289/mo

Input $0.300/M · Output $2.50/M

Grok 3

xAI

$2,283/mo

Input $3.00/M · Output $15.00/M

At this workload, Gemini 2.5 Flash is 87% cheaper than Grok 3 — a savings of $1,994/month ($23,924/year).

Production recipe — Agent Command Center

strategy: cost-optimized
primary:
  model: gemini-2-5-flash
  provider: vertex-ai
fallback:
  model: grok-3
  provider: xai
shadow: { sample_rate: 0.05 }   # mirror 5% of traffic to compare quality live

Get started free →Routing docs ↗

	Gemini 2.5 Flash Google Vertex AI	Grok 3 xAI
Input price	$0.300/M	$3.00/M
Output price	$2.50/M	$15.00/M
Context window	1,048,576	131,072
Max output	65,535	131,072
Function calling	✓	✓
Vision	✓	—
Audio input	—	—
Reasoning	✓	—
Prompt caching	✓	✓
Structured output	✓	—
Pricing verified	May 12, 2026	May 12, 2026