Model Comparison

GPT-3.5 Turbo vs Phi-3.5-mini-instructWhich is better in 2026?

GPT-3.5 Turbo significantly outperforms across most benchmarks. Phi-3.5-mini-instruct is 7.5x cheaper per token.

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

GPT-3.5 Turbo (by OpenAI) and Phi-3.5-mini-instruct (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-3.5 Turbo outperforms in 4 benchmarks (GPQA, HumanEval, MGSM, MMLU), while Phi-3.5-mini-instruct is better at 1 benchmark (MATH). GPT-3.5 Turbo significantly outperforms across most benchmarks.

On price, Phi-3.5-mini-instruct is roughly 7.5x 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 GPT-3.5 Turbo if…

  • you want the strongest raw capability — it leads on 4 of 5 shared benchmarks

Choose Phi-3.5-mini-instruct if…

  • cost matters — it's about 7.5x cheaper per token
  • you process long inputs — it offers a 128,000 token context window
  • you want the most recent training data — it shipped Aug 2024
  • you need open weights you can self-host or fine-tune
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Performance Benchmarks

Comparative analysis across standard metrics

5 benchmarks

GPT-3.5 Turbo outperforms in 4 benchmarks (GPQA, HumanEval, MGSM, MMLU), while Phi-3.5-mini-instruct is better at 1 benchmark (MATH).

GPT-3.5 Turbo significantly outperforms across most benchmarks.

Wed Jun 10 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Phi-3.5-mini-instruct costs less

For input processing, GPT-3.5 Turbo ($0.50/1M tokens) is 5.0x more expensive than Phi-3.5-mini-instruct ($0.10/1M tokens).

For output processing, GPT-3.5 Turbo ($1.50/1M tokens) is 15.0x more expensive than Phi-3.5-mini-instruct ($0.10/1M tokens).

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

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

Lowest available price from all providers
Wed Jun 10 2026 • llm-stats.com
OpenAI
GPT-3.5 Turbo
Input tokens$0.50
Output tokens$1.50
Best providerAzure
Microsoft
Phi-3.5-mini-instruct
Input tokens$0.10
Output tokens$0.10
Best providerAzure
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Phi-3.5-mini-instruct accepts 128,000 input tokens compared to GPT-3.5 Turbo's 16,385 tokens. Phi-3.5-mini-instruct can generate longer responses up to 128,000 tokens, while GPT-3.5 Turbo is limited to 4,096 tokens.

OpenAI
GPT-3.5 Turbo
Input16,385 tokens
Output4,096 tokens
Microsoft
Phi-3.5-mini-instruct
Input128,000 tokens
Output128,000 tokens
Wed Jun 10 2026 • llm-stats.com

License

Usage and distribution terms

GPT-3.5 Turbo is licensed under a proprietary license, while Phi-3.5-mini-instruct uses MIT.

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

GPT-3.5 Turbo

Proprietary

Closed source

Phi-3.5-mini-instruct

MIT

Open weights

Release Timeline

When each model was launched

GPT-3.5 Turbo was released on 2023-03-21, while Phi-3.5-mini-instruct was released on 2024-08-23.

Phi-3.5-mini-instruct is 17 months newer than GPT-3.5 Turbo.

GPT-3.5 Turbo

Mar 21, 2023

3.2 years ago

Phi-3.5-mini-instruct

Aug 23, 2024

1.8 years ago

1.4yr newer

Knowledge Cutoff

When training data ends

GPT-3.5 Turbo has a documented knowledge cutoff of 2021-09-30, while Phi-3.5-mini-instruct's cutoff date is not specified.

We can confirm GPT-3.5 Turbo's training data extends to 2021-09-30, but cannot make a direct comparison without Phi-3.5-mini-instruct's cutoff date.

GPT-3.5 Turbo

Sep 2021

Phi-3.5-mini-instruct

—

Provider Availability

GPT-3.5 Turbo is available from Azure, OpenAI. Phi-3.5-mini-instruct is available from Azure.

GPT-3.5 Turbo

azure logo
Azure
Input Price:Input: $0.50/1MOutput Price:Output: $1.50/1M
openai logo
OpenAI
Input Price:Input: $0.50/1MOutput Price:Output: $1.50/1M

Phi-3.5-mini-instruct

azure logo
Azure
Input Price:Input: $0.10/1MOutput Price:Output: $0.10/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

OpenAI
Higher GPQA score (30.8% vs 30.4%)
Higher HumanEval score (68.0% vs 62.8%)
Higher MGSM score (56.3% vs 47.9%)
Higher MMLU score (69.8% vs 69.0%)
Microsoft
Larger context window (128,000 tokens)
Less expensive input tokens
Less expensive output tokens
Has open weights
Higher MATH score (48.5% vs 43.1%)

Detailed Comparison

AI Model Comparison Table
Feature
OpenAI
GPT-3.5 Turbo
Microsoft
Phi-3.5-mini-instruct

FAQ

Common questions about GPT-3.5 Turbo vs Phi-3.5-mini-instruct.

Which is better, GPT-3.5 Turbo or Phi-3.5-mini-instruct?

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

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

GPT-3.5 Turbo scores DROP: 70.2%, MMLU: 69.8%, HumanEval: 68.0%, MGSM: 56.3%, MATH: 43.1%. Phi-3.5-mini-instruct scores GSM8k: 86.2%, ARC-C: 84.6%, RULER: 84.1%, PIQA: 81.0%, OpenBookQA: 79.2%.

Is GPT-3.5 Turbo cheaper than Phi-3.5-mini-instruct?

Phi-3.5-mini-instruct is 5.0x cheaper for input tokens. GPT-3.5 Turbo costs $0.50/M input and $1.50/M output via azure. Phi-3.5-mini-instruct costs $0.10/M input and $0.10/M output via azure.

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

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

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

Key differences include context window (16K vs 128K), input pricing ($0.50 vs $0.10/M), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-3.5 Turbo and Phi-3.5-mini-instruct?

GPT-3.5 Turbo is developed by OpenAI and Phi-3.5-mini-instruct is developed by Microsoft.

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