Model Comparison
o1 vs Phi 4 Reasoning PlusWhich is better in 2026?
Both models are evenly matched across the benchmarks.
Verdict: o1 vs Phi 4 Reasoning Plus — which is better?
o1 (by OpenAI) and Phi 4 Reasoning Plus (by Microsoft) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
o1 outperforms in 1 benchmarks (GPQA), while Phi 4 Reasoning Plus is better at 1 benchmark (AIME 2024). Both models are evenly matched across the benchmarks.
Choose o1 if…
- you want predictable pricing at $15.00/M input and $60.00/M output
Choose Phi 4 Reasoning Plus if…
- you want the most recent training data — it shipped Apr 2025
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
o1 outperforms in 1 benchmarks (GPQA), while Phi 4 Reasoning Plus is better at 1 benchmark (AIME 2024).
Both models are evenly matched across the benchmarks.
Arena Performance
Human preference votes
Context Window
Maximum input and output token capacity
Only o1 specifies input context (200,000 tokens). Only o1 specifies output context (100,000 tokens).
License
Usage and distribution terms
o1 is licensed under a proprietary license, while Phi 4 Reasoning Plus uses MIT.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
MIT
Open weights
Release Timeline
When each model was launched
o1 was released on 2024-12-17, while Phi 4 Reasoning Plus was released on 2025-04-30.
Phi 4 Reasoning Plus is 4 months newer than o1.
Dec 17, 2024
1.6 years ago
Apr 30, 2025
1.3 years ago
4mo newerKnowledge Cutoff
When training data ends
Phi 4 Reasoning Plus has a documented knowledge cutoff of 2025-03-01, while o1's cutoff date is not specified.
We can confirm Phi 4 Reasoning Plus's training data extends to 2025-03-01, but cannot make a direct comparison without o1's cutoff date.
—
Mar 2025
Outputs Comparison
Key Takeaways
o1
View detailsOpenAI
Phi 4 Reasoning Plus
View detailsMicrosoft
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against o1 and Phi 4 Reasoning Plus side-by-side, then vote on the output you prefer.
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FAQ
Common questions about o1 vs Phi 4 Reasoning Plus.