OpenLuxGemini 3.1 Flash Image Preview vs FLUX 2 Pro
Gemini 3.1 Flash Image Preview and FLUX 2 Pro both run on OpenLux behind one OpenAI-compatible endpoint. Gemini 3.1 Flash Image Preview is metered at $0.0122 per request (-92% vs official rates); FLUX 2 Pro at $0.021 per request. Gemini 3.1 Flash Image Preview is the lower-cost option per unit — about 42% cheaper on the same OpenLux endpoint. This page compares their rates, strengths and best-fit workloads so you can route each request to the right model.
The short version
In practice the two models are complements, not substitutes: Gemini 3.1 Flash Image Preview suits workloads that need image generation and creative pipelines. FLUX 2 Pro is the better fit when you need image editing that takes reference images, image generation and creative pipelines. Both are called with the same OpenLux key, so switching between them is a one-field change to the model name.
Choose Gemini 3.1 Flash Image Preview when
- You need image generation and creative pipelines.
- Unit cost is the deciding factor for this workload.
Choose FLUX 2 Pro when
- You need image editing that takes reference images.
- You need image generation and creative pipelines.
Rates on OpenLux
| Model | Provider | Rate | Discount |
|---|---|---|---|
| Gemini 3.1 Flash Image Preview | $0.0122 per request | -92% | |
| FLUX 2 Pro | Flux | $0.021 per request | — |
Rates follow official provider pricing and are billed in USD. See the full catalogue and pricing plans for credit allowances.
One snippet, two models
Gemini 3.1 Flash Image Preview and FLUX 2 Pro share the same OpenAI-compatible request shape. Run the same code against both and compare the answers on your own workload.
from openai import OpenAI
client = OpenAI(
api_key="sk-openlux-...",
base_url="https://openlux.lol/v1",
)
for model in ["gemini-3.1-flash-image-preview", "flux-2-pro"]:
resp = client.chat.completions.create(
model=model,
messages=[{"role": "user", "content": "Summarise this release note for me."}],
)
print(model, "->", resp.choices[0].message.content)Any OpenAI SDK works the same way — see the docs for streaming, tools and error codes.
Gemini 3.1 Flash Image Preview vs FLUX 2 Pro questions
How much do Gemini 3.1 Flash Image Preview and FLUX 2 Pro cost on OpenLux?
Gemini 3.1 Flash Image Preview is metered pay as you go at $0.0122 per request, a -92% discount on official list pricing. FLUX 2 Pro is metered at $0.021 per request. There is no subscription requirement: usage is billed in USD and every request is visible in the console.
Can I call Gemini 3.1 Flash Image Preview and FLUX 2 Pro with the same API key?
Yes. Both models sit behind the same OpenAI-compatible endpoint at https://openlux.lol/v1. Keep the same key and change only the "model" field to switch between gemini-3.1-flash-image-preview and flux-2-pro — request and response shapes stay identical.
Which is cheaper, Gemini 3.1 Flash Image Preview or FLUX 2 Pro?
Gemini 3.1 Flash Image Preview costs less per unit: $0.0122 per request versus $0.021 per request, about 42% lower for the same volume. Over a month of production traffic the difference compounds, and the console shows cost per request in real time.
When should I pick Gemini 3.1 Flash Image Preview over FLUX 2 Pro?
In practice the two models are complements, not substitutes: Gemini 3.1 Flash Image Preview suits workloads that need image generation and creative pipelines. FLUX 2 Pro is the better fit when you need image editing that takes reference images, image generation and creative pipelines. Both are called with the same OpenLux key, so switching between them is a one-field change to the model name.
Keep comparing
More head-to-head pages that pair well with this one.
GPT Image 2 C vs Gemini 3.1 Flash Image Preview
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Gemini 3 Pro Image Preview vs Gemini 3.1 Flash Image Preview
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GPT Image 2 C vs FLUX 2 Pro
Rates, strengths and which model to pick.
Gemini 3 Pro Image Preview vs FLUX 2 Pro
Rates, strengths and which model to pick.
Route every request to the right model
OpenLux keeps Gemini 3.1 Flash Image Preview, FLUX 2 Pro and every other model behind one key, one endpoint and one bill. Start with free trial credit and switch models without touching your code.