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Phi-3.5-mini-instruct vs Phi 4

Phi 4 leads the LLM Stats Score 5.4 to -3.8. Phi 4 is 1.1x cheaper per token.

Microsoft · Microsoft · Updated for 2026

Which is better?

Phi 4 leads the overall LLM Stats Score 5.4 to -3.8, ranking #296 overall.

In the 7 individual benchmarks reported for both models, Phi 4 wins 7; this is a narrower head-to-head signal than the composite indexes.

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.

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

Choose Phi-3.5-mini-instruct

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

Choose Phi 4

  • overall performance matters — it scores 5.4 and ranks #296 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 7 of 7 exact shared results
  • cost matters — it's about 1.1x cheaper per token
  • you want the most recent training data — it shipped Dec 2024

At a glance

The differences that matter most.

Core performance indexes
-3.8
#346
5.4
#296
-4.7
#342
6.5
#287
-6.8
#261
3.4
#217
Cost, coverage & limits
Benchmark wins
0 of 7
7 of 7
Input price
$0.10 / M
$0.07 / M
Output price
$0.10 / M
$0.14 / M
Context window
128,000
16,384

Capability indexes

Additional strengths measured across groups of related public benchmarks

3 shared
Index
Phi-3.5-mini-instruct
Phi 4
-1.5#304
12.8#230
0.6#196
12.9#137
0.6#182
12.9#120
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

31 reported for Phi-3.5-mini-instruct · 13 for Phi 4

7 shared

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.

Wed Sep 16 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

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
Wed Sep 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 16,384 tokens. Phi-3.5-mini-instruct can generate longer responses up to 128,000 tokens, while Phi 4 is limited to 16,384 tokens.

Microsoft
Phi-3.5-mini-instruct
Input128,000 tokens
Output128,000 tokens
Microsoft
Phi 4
Input16,384 tokens
Output16,384 tokens
Wed Sep 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

2.1 years ago

Phi 4

Dec 12, 2024

1.8 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

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against Phi-3.5-mini-instruct and Phi 4 side-by-side, then vote on the output you prefer.

Phi-3.5-mini-instruct
✓ Preferred
Phi 4
Open in Playground

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 leads the LLM Stats Score 5.4 to -3.8. 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 capability indexes, individual benchmarks, pricing, and limits 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 LLM Stats Score (-3.8 vs 5.4), context window (128K vs 16K), input pricing ($0.10 vs $0.07/M). See the full comparison above for benchmark-by-benchmark results.