Model Comparison
GPT-4.1 mini vs Phi-3.5-mini-instructWhich is better in 2026?
GPT-4.1 mini significantly outperforms across most benchmarks. Phi-3.5-mini-instruct is 7.0x cheaper per token.
Verdict: GPT-4.1 mini vs Phi-3.5-mini-instruct — which is better?
GPT-4.1 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-4.1 mini outperforms in 3 benchmarks (GPQA, MMLU, MMMLU), while Phi-3.5-mini-instruct is better at 0 benchmarks. GPT-4.1 mini significantly outperforms across most benchmarks.
On price, Phi-3.5-mini-instruct is roughly 7.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-4.1 mini also accepts a larger context window (1,047,576 input tokens), making it the stronger choice for long documents and large codebases.
Choose GPT-4.1 mini if…
- you want the strongest raw capability — it leads on 3 of 3 shared benchmarks
- you process long inputs — it offers a 1,047,576 token context window
- you want the most recent training data — it shipped Apr 2025
Choose Phi-3.5-mini-instruct if…
- cost matters — it's about 7.0x cheaper per token
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
GPT-4.1 mini outperforms in 3 benchmarks (GPQA, MMLU, MMMLU), while Phi-3.5-mini-instruct is better at 0 benchmarks.
GPT-4.1 mini significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-4.1 mini ($0.40/1M tokens) is 4.0x more expensive than Phi-3.5-mini-instruct ($0.10/1M tokens).
For output processing, GPT-4.1 mini ($1.60/1M tokens) is 16.0x more expensive than Phi-3.5-mini-instruct ($0.10/1M tokens).
In conclusion, GPT-4.1 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
GPT-4.1 mini accepts 1,047,576 input tokens compared to Phi-3.5-mini-instruct's 128,000 tokens. Phi-3.5-mini-instruct can generate longer responses up to 128,000 tokens, while GPT-4.1 mini is limited to 32,768 tokens.
Input Capabilities
Supported data types and modalities
GPT-4.1 mini supports multimodal inputs, whereas Phi-3.5-mini-instruct does not.
GPT-4.1 mini can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT-4.1 mini
Phi-3.5-mini-instruct
License
Usage and distribution terms
GPT-4.1 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-4.1 mini was released on 2025-04-14, while Phi-3.5-mini-instruct was released on 2024-08-23.
GPT-4.1 mini is 8 months newer than Phi-3.5-mini-instruct.
Apr 14, 2025
1.1 years ago
7mo newerAug 23, 2024
1.8 years ago
Knowledge Cutoff
When training data ends
GPT-4.1 mini has a documented knowledge cutoff of 2024-05-31, while Phi-3.5-mini-instruct's cutoff date is not specified.
We can confirm GPT-4.1 mini's training data extends to 2024-05-31, but cannot make a direct comparison without Phi-3.5-mini-instruct's cutoff date.
May 2024
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Provider Availability
GPT-4.1 mini is available from OpenAI. Phi-3.5-mini-instruct is available from Azure.
GPT-4.1 mini
Phi-3.5-mini-instruct
Outputs Comparison
Key Takeaways
GPT-4.1 mini
View detailsOpenAI
Phi-3.5-mini-instruct
View detailsMicrosoft
Detailed Comparison
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FAQ
Common questions about GPT-4.1 mini vs Phi-3.5-mini-instruct.