o3 vs o3 Pro

Compare o3 and o3 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

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Feature o3 o3 Pro
CategoryReasoningReasoning
Parameters~1T~1T
Context Window200K200K
Input Price$0.10/1M tokens$0.15/1M tokens
Output Price$0.40/1M tokens$0.60/1M tokens
Latency~2000ms~5000ms

Choose o3 when:

  • ✓ Complex calculations
  • ✓ Multi-factor analysis
  • ✓ Research-grade work
Key Strengths:

Extended thinking, Complex logic, Mathematical reasoning

Choose o3 Pro when:

  • ✓ Research-grade reasoning
  • ✓ Mathematical proofs
  • ✓ Hardest problems
Key Strengths:

Deepest reasoning, Best for hard problems, Highest accuracy

Verdict: o3 vs o3 Pro

For cost efficiency, o3 wins at $0.10/1M input tokens. For speed, o3 is faster at ~2000ms. o3 excels at Complex calculations while o3 Pro is better for Research-grade reasoning. 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. o3 Pro costs $0.15 input and $0.60 output. o3 is 1.5x 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. o3 Pro offers 200K context at ~5000ms. Both have identical context windows.

Best For

o3 (Reasoning) is optimized for: Complex calculations, Multi-factor analysis, Research-grade work. o3 Pro (Reasoning) works best for: Research-grade reasoning, Mathematical proofs, Hardest problems.

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 o3 Pro
response_b = client.chat.completions.create(
    model="o3-pro",
    messages=[{"role": "user", "content": "Your question here"}]
)

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Get API Key Try in Playground

Frequently Asked Questions

Which is better, o3 or o3 Pro?

o3 (Reasoning, ~1T) offers Extended thinking. o3 Pro (Reasoning, ~1T) offers Deepest reasoning. Choose o3 for Complex calculations or o3 Pro for Research-grade reasoning.

How much does o3 cost vs o3 Pro?

o3: $0.10/1M input, $0.40/1M output. o3 Pro: $0.15/1M input, $0.60/1M 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 o3 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.