compare/FLUX 3 Image KleinvsGemini 3.1 Pro

FLUX 3 Image Klein vs Gemini 3.1 Pro

Pricing, context window, capabilities, and release date — pulled from each provider's public docs. Both are available via the same AIgateway OpenAI-compatible endpoint; flip the model string to switch.

RUN BOTH LIVE

Paste a prompt. Watch them race.

Both models stream in parallel through your own AIgateway key. Tokens, latency, and cost update as they arrive.

Sign in to runLive streaming uses your own key. It's free to sign up.
 FLUX 3 Image Klein
black-forest-labs/flux-3-image-klein
Gemini 3.1 Pro
google/gemini-3.1-pro
ProviderBlack Forest LabsGoogle
FamilyFLUXGemini 3
Modalityimagetext
Context window—1,000,000 tok
Max output—65,536 tok
Released2026-10-162026-05-22
Input price$0.0090 /img$2.00 /1M
Output price—$12.00 /1M
Cache read—$0.200 /1M
Tools—yes
Streaming—yes
Vision—yes
JSON mode—yes
Reasoning—yes
Prompt caching—yes
FLUX 3 Image Klein
black-forest-labs/flux-3-image-klein
Full spec →

FLUX 3 Image Klein is Black Forest Labs' 5.6B-parameter image model for text-to-image, image editing, and multi-reference generation with up to 10 reference images. It supports native 4K output and bounding-box layout control.

Strengths
  • Text-to-image generation
  • Creative control
Gemini 3.1 Pro
google/gemini-3.1-pro
Full spec →

Google's most intelligent Gemini model with improved reasoning, a medium thinking level, and a 1M token context window.

Strengths
  • 2M-token context
  • Native video + audio input
  • Cheapest long-context reasoning
SWITCH BETWEEN THEM

One key, both models, one line different.

# pip install aigateway-py openai
# aigateway-py: sub-accounts, evals, replays, jobs, webhook verify.
# openai SDK: chat/embeddings/images/audio — drop-in compat per our SDK's own guidance.
from openai import OpenAI

client = OpenAI(
    base_url="https://api.aigateway.sh/v1",
    api_key="sk-aig-...",
)

# Try FLUX 3 Image Klein
client.chat.completions.create(
    model="black-forest-labs/flux-3-image-klein",
    messages=[{"role":"user","content":"hello"}],
)

# Try Gemini 3.1 Pro — same client, same key
client.chat.completions.create(
    model="google/gemini-3.1-pro",
    messages=[{"role":"user","content":"hello"}],
)
Get an AIgateway keyAdd a third model

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