Model Comparison
GPT-5.6 Terra vs Phi 4 Reasoning PlusWhich is better in 2026?
GPT-5.6 Terra significantly outperforms across most benchmarks.
Verdict: GPT-5.6 Terra vs Phi 4 Reasoning Plus — which is better?
GPT-5.6 Terra (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.
GPT-5.6 Terra outperforms in 1 benchmarks (GPQA), while Phi 4 Reasoning Plus is better at 0 benchmarks. GPT-5.6 Terra significantly outperforms across most benchmarks.
Choose GPT-5.6 Terra if…
- you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
- you want the most recent training data — it shipped Jul 2026
Choose Phi 4 Reasoning Plus if…
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
GPT-5.6 Terra outperforms in 1 benchmarks (GPQA), while Phi 4 Reasoning Plus is better at 0 benchmarks.
GPT-5.6 Terra significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Context Window
Maximum input and output token capacity
Only GPT-5.6 Terra specifies input context (1,050,000 tokens). Only GPT-5.6 Terra specifies output context (128,000 tokens).
Input Capabilities
Supported data types and modalities
GPT-5.6 Terra supports multimodal inputs, whereas Phi 4 Reasoning Plus does not.
GPT-5.6 Terra can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT-5.6 Terra
Phi 4 Reasoning Plus
License
Usage and distribution terms
GPT-5.6 Terra 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
GPT-5.6 Terra was released on 2026-07-09, while Phi 4 Reasoning Plus was released on 2025-04-30.
GPT-5.6 Terra is 15 months newer than Phi 4 Reasoning Plus.
Jul 9, 2026
1 weeks ago
1.2yr newerApr 30, 2025
1.2 years ago
Knowledge Cutoff
When training data ends
GPT-5.6 Terra has a knowledge cutoff of 2026-02-16, while Phi 4 Reasoning Plus has a cutoff of 2025-03-01.
GPT-5.6 Terra has more recent training data (up to 2026-02-16), making it potentially better informed about events through that date compared to Phi 4 Reasoning Plus (2025-03-01).
Feb 2026
11 mo newerMar 2025
Outputs Comparison
Key Takeaways
Phi 4 Reasoning Plus
View detailsMicrosoft
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against GPT-5.6 Terra and Phi 4 Reasoning Plus side-by-side, then vote on the output you prefer.
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FAQ
Common questions about GPT-5.6 Terra vs Phi 4 Reasoning Plus.