Gemini 3.5 Flash vs Grok 4.3

Both are Mid-tier models, from Google and xAI respectively. Grok 4.3 is the cheaper choice overall at a 4:1 input:output ratio.

Which is cheaper

Input price: Grok 4.3 is cheaper ($1.25 vs $1.50).
Output price: Grok 4.3 is cheaper ($2.50 vs $9.00).
Blended, 4:1 input:output ratio: Grok 4.3 is 50% cheaper ($1.50 vs $3.00 per weighted 1M tokens).

Side by side

Spec	Gemini 3.5 Flash	Grok 4.3
Provider	Google	xAI
Tier	Mid	Mid
Context window	1.05M	1M
Max output	66K	—
Input $/1M	$1.50	$1.25
Output $/1M	$9.00	$2.50
Cache read $/1M	$0.15	$0.20
Modalities	text, image	text, image

Gemini 3.5 Flash. Standard tier, not introductory pricing. Cached context is billed for storage at $1 per 1M tokens per hour.

Grok 4.3. Short-context rate, for prompts under 200K tokens. At 200K and above: $2.50 input / $5 output, cache read $0.40 per 1M. Eligible for a 20% Batch API discount.

Sources

Gemini 3.5 Flash — verified August 29, 2026

Grok 4.3 — verified August 29, 2026

Full Gemini 3.5 Flash pricing page → · Full Grok 4.3 pricing page →