Model Comparison

Phi-3.5-mini-instruct vs Phi 4Which is better in 2026?

Phi 4 significantly outperforms across most benchmarks. Phi 4 is 1.1x cheaper per token.

Verdict: Phi-3.5-mini-instruct vs Phi 4 — which is better?

Phi-3.5-mini-instruct (by Microsoft) and Phi 4 (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.

Phi-3.5-mini-instruct outperforms in 0 benchmarks, while Phi 4 is better at 7 benchmarks (Arena Hard, GPQA, HumanEval, MATH, MGSM, MMLU, MMLU-Pro). Phi 4 significantly outperforms across most benchmarks.

On price, Phi 4 is roughly 1.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Phi-3.5-mini-instruct also accepts a larger context window (128,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Phi-3.5-mini-instruct if…

  • you process long inputs — it offers a 128,000 token context window

Choose Phi 4 if…

  • you want the strongest raw capability — it leads on 7 of 7 shared benchmarks
  • cost matters — it's about 1.1x cheaper per token
  • you want the most recent training data — it shipped Dec 2024
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Performance Benchmarks

Comparative analysis across standard metrics

7 benchmarks

Phi-3.5-mini-instruct outperforms in 0 benchmarks, while Phi 4 is better at 7 benchmarks (Arena Hard, GPQA, HumanEval, MATH, MGSM, MMLU, MMLU-Pro).

Phi 4 significantly outperforms across most benchmarks.

Tue Jun 16 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Phi 4 costs less

For input processing, Phi-3.5-mini-instruct ($0.10/1M tokens) is 1.4x more expensive than Phi 4 ($0.07/1M tokens).

For output processing, Phi-3.5-mini-instruct ($0.10/1M tokens) is 1.4x cheaper than Phi 4 ($0.14/1M tokens).

In conclusion, Phi-3.5-mini-instruct is more expensive than Phi 4.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Tue Jun 16 2026 • llm-stats.com
Microsoft
Phi-3.5-mini-instruct
Input tokens$0.10
Output tokens$0.10
Best providerAzure
Microsoft
Phi 4
Input tokens$0.07
Output tokens$0.14
Best providerDeepinfra
Notice missing or incorrect data?Start an Issue→

Model Size

Parameter count comparison

10.9B diff

Phi 4 has 10.9B more parameters than Phi-3.5-mini-instruct, making it 286.8% larger.

Microsoft
Phi-3.5-mini-instruct
3.8Bparameters
Microsoft
Phi 4
14.7Bparameters
3.8B
Phi-3.5-mini-instruct
14.7B
Phi 4

Context Window

Maximum input and output token capacity

Phi-3.5-mini-instruct accepts 128,000 input tokens compared to Phi 4's 16,000 tokens. Phi-3.5-mini-instruct can generate longer responses up to 128,000 tokens, while Phi 4 is limited to 16,000 tokens.

Microsoft
Phi-3.5-mini-instruct
Input128,000 tokens
Output128,000 tokens
Microsoft
Phi 4
Input16,000 tokens
Output16,000 tokens
Tue Jun 16 2026 • llm-stats.com

License

Usage and distribution terms

Both models are licensed under MIT.

Both models share the same licensing terms, providing consistent usage rights.

Phi-3.5-mini-instruct

MIT

Open weights

Phi 4

MIT

Open weights

Release Timeline

When each model was launched

Phi-3.5-mini-instruct was released on 2024-08-23, while Phi 4 was released on 2024-12-12.

Phi 4 is 4 months newer than Phi-3.5-mini-instruct.

Phi-3.5-mini-instruct

Aug 23, 2024

1.8 years ago

Phi 4

Dec 12, 2024

1.5 years ago

3mo newer

Knowledge Cutoff

When training data ends

Phi 4 has a documented knowledge cutoff of 2024-06-01, while Phi-3.5-mini-instruct's cutoff date is not specified.

We can confirm Phi 4's training data extends to 2024-06-01, but cannot make a direct comparison without Phi-3.5-mini-instruct's cutoff date.

Phi-3.5-mini-instruct

—

Phi 4

Jun 2024

Provider Availability

Phi-3.5-mini-instruct is available from Azure. Phi 4 is available from DeepInfra.

Phi-3.5-mini-instruct

azure logo
Azure
Input Price:Input: $0.10/1MOutput Price:Output: $0.10/1M

Phi 4

deepinfra logo
Deepinfra
Input Price:Input: $0.07/1MOutput Price:Output: $0.14/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

Microsoft
Larger context window (128,000 tokens)
Less expensive output tokens
Microsoft
Less expensive input tokens
Higher Arena Hard score (75.4% vs 37.0%)
Higher GPQA score (56.1% vs 30.4%)
Higher HumanEval score (82.6% vs 62.8%)
Higher MATH score (80.4% vs 48.5%)
Higher MGSM score (80.6% vs 47.9%)
Higher MMLU score (84.8% vs 69.0%)
Higher MMLU-Pro score (70.4% vs 47.4%)

Detailed Comparison

AI Model Comparison Table
Feature
Microsoft
Phi-3.5-mini-instruct
Microsoft
Phi 4

FAQ

Common questions about Phi-3.5-mini-instruct vs Phi 4.

Which is better, Phi-3.5-mini-instruct or Phi 4?

Phi 4 significantly outperforms across most benchmarks. Phi-3.5-mini-instruct is made by Microsoft and Phi 4 is made by Microsoft. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Phi-3.5-mini-instruct compare to Phi 4 in benchmarks?

Phi-3.5-mini-instruct scores GSM8k: 86.2%, ARC-C: 84.6%, RULER: 84.1%, PIQA: 81.0%, OpenBookQA: 79.2%. Phi 4 scores MMLU: 84.8%, HumanEval+: 82.8%, HumanEval: 82.6%, MGSM: 80.6%, MATH: 80.4%.

Is Phi-3.5-mini-instruct cheaper than Phi 4?

Phi 4 is 1.4x cheaper for input tokens. Phi-3.5-mini-instruct costs $0.10/M input and $0.10/M output via azure. Phi 4 costs $0.07/M input and $0.14/M output via deepinfra.

What are the context window sizes for Phi-3.5-mini-instruct and Phi 4?

Phi-3.5-mini-instruct supports 128K tokens and Phi 4 supports 16K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Phi-3.5-mini-instruct and Phi 4?

Key differences include context window (128K vs 16K), input pricing ($0.10 vs $0.07/M). See the full comparison above for benchmark-by-benchmark results.

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