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GPT-5.1 Thinking vs Phi-3.5-MoE-instruct

GPT-5.1 Thinking leads the LLM Stats Score 36.6 to 1.9.

OpenAI · Microsoft · Updated for 2026

Which is better?

GPT-5.1 Thinking leads the overall LLM Stats Score 36.6 to 1.9, ranking #74 overall.

In the 1 individual benchmarks reported for both models, GPT-5.1 Thinking wins 1; this is a narrower head-to-head signal than the composite indexes.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose GPT-5.1 Thinking

  • overall performance matters — it scores 36.6 and ranks #74 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results
  • you want the most recent training data — it shipped Nov 2025

Choose Phi-3.5-MoE-instruct

  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Core performance indexes
36.6
#74
1.9
#318
36.3
#73
1.4
#311
21.6
#86
-3.8
#254
Cost, coverage & limits
Benchmark wins
1 of 1
0 of 1
Input price
$1.25 / M
— / M
Output price
$10.00 / M
— / M
Context window
400,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
GPT-5.1 Thinking
Phi-3.5-MoE-instruct
30.0#78
4.3#284
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

9 reported for GPT-5.1 Thinking · 31 for Phi-3.5-MoE-instruct

1 shared

GPT-5.1 Thinking outperforms in 1 benchmarks (GPQA), while Phi-3.5-MoE-instruct is better at 0 benchmarks.

GPT-5.1 Thinking significantly outperforms across most benchmarks.

Mon Sep 21 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only GPT-5.1 Thinking specifies input context (400,000 tokens). Only GPT-5.1 Thinking specifies output context (128,000 tokens).

OpenAI
GPT-5.1 Thinking
Input400,000 tokens
Output128,000 tokens
Microsoft
Phi-3.5-MoE-instruct
Input- tokens
Output- tokens
Mon Sep 21 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

GPT-5.1 Thinking supports multimodal inputs, whereas Phi-3.5-MoE-instruct does not.

GPT-5.1 Thinking can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT-5.1 Thinking

Text
Images
Audio
Video

Phi-3.5-MoE-instruct

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-5.1 Thinking is licensed under a proprietary license, while Phi-3.5-MoE-instruct uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

GPT-5.1 Thinking

Proprietary

Closed source

Phi-3.5-MoE-instruct

MIT

Open weights

Release Timeline

When each model was launched

GPT-5.1 Thinking was released on 2025-11-12, while Phi-3.5-MoE-instruct was released on 2024-08-23.

GPT-5.1 Thinking is 15 months newer than Phi-3.5-MoE-instruct.

GPT-5.1 Thinking

Nov 12, 2025

10 months ago

1.2yr newer
Phi-3.5-MoE-instruct

Aug 23, 2024

2.1 years ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against GPT-5.1 Thinking and Phi-3.5-MoE-instruct side-by-side, then vote on the output you prefer.

GPT-5.1 Thinking
✓ Preferred
Phi-3.5-MoE-instruct
Open in Playground

FAQ

Common questions about GPT-5.1 Thinking vs Phi-3.5-MoE-instruct.

Which is better, GPT-5.1 Thinking or Phi-3.5-MoE-instruct?

GPT-5.1 Thinking leads the LLM Stats Score 36.6 to 1.9. GPT-5.1 Thinking is made by OpenAI and Phi-3.5-MoE-instruct is made by Microsoft. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does GPT-5.1 Thinking compare to Phi-3.5-MoE-instruct in benchmarks?

GPT-5.1 Thinking scores Tau2 Telecom: 95.6%, AIME 2025: 94.0%, BrowseComp Long Context 128k: 90.0%, GPQA: 88.1%, MMMU: 85.4%. Phi-3.5-MoE-instruct scores ARC-C: 91.0%, OpenBookQA: 89.6%, GSM8k: 88.7%, PIQA: 88.6%, RULER: 87.1%.

What are the context window sizes for GPT-5.1 Thinking and Phi-3.5-MoE-instruct?

GPT-5.1 Thinking supports 400K tokens and Phi-3.5-MoE-instruct supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-5.1 Thinking and Phi-3.5-MoE-instruct?

Key differences include LLM Stats Score (36.6 vs 1.9), multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.1 Thinking and Phi-3.5-MoE-instruct?

GPT-5.1 Thinking is developed by OpenAI and Phi-3.5-MoE-instruct is developed by Microsoft.