Live pricing — last refreshed Apr 21, 2026

Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) vs OpenAI: GPT-4o

Head-to-head API pricing and cost comparison between Google’s Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) and OpenAI’s OpenAI: GPT-4o. Prices auto-refresh daily from OpenRouter.

Verdict

Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) is 80% cheaper for input tokens; Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) also wins on output tokens.

Side-by-side comparison

SpecGoogle: Nano Banana 2 (Gemini 3.1 Flash Image Preview)OpenAI: GPT-4o
Input price (per 1M)$0.50$2.50
Cached input (per 1M)
Output price (per 1M)$3.00$10.00
Batch input (per 1M)$1.25
Batch output (per 1M)$5.00
Reasoning price (per 1M)
Context window66K128K
Vision supportYesYes
Caching supportNoNo
Batch APINoYes
Reasoning capabilityNoNo

Monthly cost at volume

Estimated monthly API spend at common production traffic levels (input/output tokens per request shown).

VolumeGoogle: Nano Banana 2 (Gemini 3.1 Flash Image Preview)OpenAI: GPT-4oSavings
1K req/day
500in / 200out tokens
$25.50$97.50$72.00
Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) wins
10K req/day
1500in / 500out tokens
$675.00$2,625$1,950
Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) wins
100K req/day
3000in / 800out tokens
$11,700$46,500$34,800
Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) wins
1M req/day
8000in / 2000out tokens
$300,000$1,200,000$900,000
Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) wins
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Adjust input/output token counts, request volume, batch & cached pricing.

Related comparisons

Frequently asked questions

Which is cheaper, Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) or OpenAI: GPT-4o?

For input tokens, Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) is roughly 80% cheaper at $0.50/1M vs $2.50/1M. For output tokens, Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) wins at $3.00/1M. Real-world cost depends on your input/output ratio — use the calculator to model your actual workload.

What’s the context window difference?

Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) has a context window of 66K tokens. OpenAI: GPT-4o offers 128K tokens. Larger context windows are valuable for long documents, RAG pipelines, and multi-turn conversations — but they come with higher input-token bills if you fill them every request.

Should I use Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) or OpenAI: GPT-4o?

Choose Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview) if you’re already on the Google stack, want broad ecosystem support, or prefer its lower input price. Choose OpenAI: GPT-4o for OpenAI’s ecosystem, native vision input, or its differentiated capabilities. Run a small benchmark on your own prompts before committing — price is only one axis.

How are these prices kept current?

Prices are pulled directly from OpenRouter’s public models API once every 24 hours via a Convex cron job, then normalized to per-1M-token figures. Last refresh: Apr 21, 2026.