o3 vs Gemini 2.5 Pro
Compare o3 and Gemini 2.5 Pro: pricing, performance, context window, latency, and best use cases. Side-by-side comparison on XALEN.
Updated 2026-05-21 · By Abhishek Raj · Our methodology
| Feature | o3 | Gemini 2.5 Pro |
|---|---|---|
| Category | Reasoning | Frontier |
| Parameters | ~1T | ~1.5T |
| Context Window | 200K | 2M |
| Input Price | $0.10/1M tokens | $0.07/1M tokens |
| Output Price | $0.40/1M tokens | $0.21/1M tokens |
| Latency | ~2000ms | ~600ms |
Choose o3 when:
- ✓ Complex calculations
- ✓ Multi-factor analysis
- ✓ Research-grade work
Extended thinking, Complex logic, Mathematical reasoning
Choose Gemini 2.5 Pro when:
- ✓ Classical text analysis
- ✓ Multi-document reports
- ✓ Research
2M context, Strong multimodal, Long text analysis
Verdict: o3 vs Gemini 2.5 Pro
For cost efficiency, Gemini 2.5 Pro wins at $0.07/1M input tokens. For speed, o3 is faster at ~2000ms. o3 excels at Complex calculations while Gemini 2.5 Pro is better for Classical text analysis. Both are available on XALEN through a single API — try them in the Playground to see which fits your workload.
Detailed Analysis
Pricing Comparison
o3 costs $0.10/1M input tokens and $0.40/1M output tokens. Gemini 2.5 Pro costs $0.07 input and $0.21 output. Gemini 2.5 Pro is 1.4x cheaper on input tokens. XALEN offers batch processing at 50% discount on both models.
Performance & Context
o3 has a 200K context window with ~2000ms latency. Gemini 2.5 Pro offers 2M context at ~600ms. Gemini 2.5 Pro has the larger context window.
Best For
o3 (Reasoning) is optimized for: Complex calculations, Multi-factor analysis, Research-grade work. Gemini 2.5 Pro (Frontier) works best for: Classical text analysis, Multi-document reports, Research.
Try Both on XALEN
Both models are available through XALEN's OpenAI-compatible API. Switch between them by changing the model parameter:
from xalen import XALEN
client = XALEN(api_key="xln_test_YOUR_KEY")
# Use o3
response_a = client.chat.completions.create(
model="o3",
messages=[{"role": "user", "content": "Your question here"}]
)
# Use Gemini 2.5 Pro
response_b = client.chat.completions.create(
model="gemini-2-5-pro",
messages=[{"role": "user", "content": "Your question here"}]
)Frequently Asked Questions
Which is better, o3 or Gemini 2.5 Pro?
o3 (Reasoning, ~1T) offers Extended thinking. Gemini 2.5 Pro (Frontier, ~1.5T) offers 2M context. Choose o3 for Complex calculations or Gemini 2.5 Pro for Classical text analysis.
How much does o3 cost vs Gemini 2.5 Pro?
o3: $0.10/1M input, $0.40/1M output. Gemini 2.5 Pro: $0.07/1M input, $0.21/1M output. Both available on XALEN with batch processing at 50% discount.
Can I use both models on XALEN?
Yes. XALEN provides 200+ models through a single OpenAI-compatible API. Switch between o3 and Gemini 2.5 Pro by changing the model parameter. No code changes needed.
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Last updated: 2026-05-21. Pricing and specifications may change. Check pricing page for latest rates.