Model Comparison
GPT-4o mini vs Phi-3.5-mini-instructWhich is better in 2026?
GPT-4o mini significantly outperforms across most benchmarks. Phi-3.5-mini-instruct is 2.6x cheaper per token.
Verdict: GPT-4o mini vs Phi-3.5-mini-instruct — which is better?
GPT-4o mini (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-4o mini outperforms in 5 benchmarks (GPQA, HumanEval, MATH, MGSM, MMLU), while Phi-3.5-mini-instruct is better at 0 benchmarks. GPT-4o mini significantly outperforms across most benchmarks.
On price, Phi-3.5-mini-instruct is roughly 2.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Choose GPT-4o mini if…
- you want the strongest raw capability — it leads on 5 of 5 shared benchmarks
Choose Phi-3.5-mini-instruct if…
- cost matters — it's about 2.6x cheaper per token
- you want the most recent training data — it shipped Aug 2024
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
GPT-4o mini outperforms in 5 benchmarks (GPQA, HumanEval, MATH, MGSM, MMLU), while Phi-3.5-mini-instruct is better at 0 benchmarks.
GPT-4o mini significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-4o mini ($0.15/1M tokens) is 1.5x more expensive than Phi-3.5-mini-instruct ($0.10/1M tokens).
For output processing, GPT-4o mini ($0.60/1M tokens) is 6.0x more expensive than Phi-3.5-mini-instruct ($0.10/1M tokens).
In conclusion, GPT-4o mini is more expensive than Phi-3.5-mini-instruct.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Both models have the same input context window of 128,000 tokens. Phi-3.5-mini-instruct can generate longer responses up to 128,000 tokens, while GPT-4o mini is limited to 16,384 tokens.
Input Capabilities
Supported data types and modalities
GPT-4o mini supports multimodal inputs, whereas Phi-3.5-mini-instruct does not.
GPT-4o mini can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT-4o mini
Phi-3.5-mini-instruct
License
Usage and distribution terms
GPT-4o mini 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.
Proprietary
Closed source
MIT
Open weights
Release Timeline
When each model was launched
GPT-4o mini was released on 2024-07-18, while Phi-3.5-mini-instruct was released on 2024-08-23.
Phi-3.5-mini-instruct is 1 month newer than GPT-4o mini.
Jul 18, 2024
1.9 years ago
Aug 23, 2024
1.8 years ago
1mo newerKnowledge Cutoff
When training data ends
GPT-4o mini has a documented knowledge cutoff of 2023-10-01, while Phi-3.5-mini-instruct's cutoff date is not specified.
We can confirm GPT-4o mini's training data extends to 2023-10-01, but cannot make a direct comparison without Phi-3.5-mini-instruct's cutoff date.
Oct 2023
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Provider Availability
GPT-4o mini is available from Azure. Phi-3.5-mini-instruct is available from Azure.
GPT-4o mini
Phi-3.5-mini-instruct
Outputs Comparison
Key Takeaways
GPT-4o mini
View detailsOpenAI
Phi-3.5-mini-instruct
View detailsMicrosoft
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against GPT-4o mini and Phi-3.5-mini-instruct side-by-side, then vote on the output you prefer.
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FAQ
Common questions about GPT-4o mini vs Phi-3.5-mini-instruct.