o3 vs Gemini 3.1 Pro

o3 and Gemini 3.1 Pro come from different camps — OpenAI versus Google — and they split most sharply on price and context. o3 runs at $2.00/$8.00 per 1M tokens with a 200K window; Gemini 3.1 Pro sits at $2.00/$12.00 with 1M of context. Neither is objectively "better" — the right pick depends on what you're shipping.

In practice: Advanced reasoning model that thinks step-by-step for complex math, science, and coding problems. Google's current flagship. Best quality for complex reasoning and multimodal tasks. Both ship through AI API Hub on an OpenAI-compatible endpoint, so you can move between them by changing a single model name — and settle the bill with USDT or USDC, no credit card required.

On cost alone, Gemini 3.1 Pro is the cheaper of the two (Same per 1M input), which adds up fast once real traffic hits. Use the calculator below to model your own volume.

→If you are building a coding-heavy AI agent → Gemini 3.1 Pro is preferred.

→If your workload involves long document reasoning or multi-step instruction following → Gemini 3.1 Pro performs better with its 1M context.

→If cost is your primary constraint → o3 provides ~0% lower cost per 1M tokens.

On performance, o3 leans into chain-of-thought and pairs it with 200K of context — enough for chain-of-thought and complex reasoning. Gemini 3.1 Pro answers with flagship model across 1M, which makes it the stronger fit when you need flagship model and 1m context. The gap is real, but it's a question of fit rather than dominance.

Pricing is where they part ways. At $2.00/$8.00 versus $2.00/$12.00 per 1M tokens, they're neck and neck. Run a typical workload of 1M requests/month at ~1K input / 500 output tokens and Gemini 3.1 Pro keeps roughly $2000.00/month in your pocket.

Our take: if cost efficiency drives the decision, o3 wins. Either way, both run through AI API Hub with USDT/USDC payments and instant activation — start with $5 and one API key covers every model.

Since both o3 and Gemini 3.1 Pro are available through AI API Hub with OpenAI-compatible API format, switching between them requires only changing the model name parameter. Your existing SDK code works without modification.

from openai import OpenAI
client = OpenAI(api_key="YOUR_KEY", base_url="https://api.apiyihe.org/v1")
# Before: response = client.chat.completions.create(model="o3", messages=[...])
# After:  response = client.chat.completions.create(model="gemini-3.1-pro", messages=[...])

import OpenAI from "openai";
const client = new OpenAI({apiKey: process.env.KEY, baseURL: "https://api.apiyihe.org/v1"});
// Before: model: "o3"
// After:  model: "gemini-3.1-pro"

curl https://api.apiyihe.org/v1/chat/completions \
  -H "Authorization: Bearer YOUR_KEY" \
  -d '{"model": "gemini-3.1-pro", "messages": [{"role":"user","content":"Hello"}]}'

💡 AI API Hub supports both models through one API key. No separate accounts needed. Pay with USDT/USDC for all models.