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GPT OSS 120B vs Phi-3.5-mini-instruct

GPT OSS 120B leads the LLM Stats Score 29.2 to -3.8. Phi-3.5-mini-instruct is 1.8x cheaper per token.

OpenAI · Microsoft · Updated for 2026

Which is better?

GPT OSS 120B leads the overall LLM Stats Score 29.2 to -3.8, ranking #123 overall.

In the 2 individual benchmarks reported for both models, GPT OSS 120B wins 2; this is a narrower head-to-head signal than the composite indexes.

On price, Phi-3.5-mini-instruct is roughly 1.8x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT OSS 120B also accepts a larger context window (131,072 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 GPT OSS 120B

  • overall performance matters — it scores 29.2 and ranks #123 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 2 of 2 exact shared results
  • you process long inputs — it offers a 131,072 token context window
  • you want the most recent training data — it shipped Aug 2025

Choose Phi-3.5-mini-instruct

  • cost matters — it's about 1.8x cheaper per token

At a glance

The differences that matter most.

Core performance indexes
29.2
#123
-3.8
#334
23.5
#155
-4.7
#331
Cost, coverage & limits
Benchmark wins
2 of 2
0 of 2
Input price
$0.09 / M
$0.10 / M
Output price
$0.45 / M
$0.10 / M
Context window
131,072
128,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
GPT OSS 120B
Phi-3.5-mini-instruct
23.9#119
-1.1#295
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

7 reported for GPT OSS 120B · 31 for Phi-3.5-mini-instruct

2 shared

GPT OSS 120B outperforms in 2 benchmarks (GPQA, MMLU), while Phi-3.5-mini-instruct is better at 0 benchmarks.

GPT OSS 120B significantly outperforms across most benchmarks.

Sun Sep 06 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Phi-3.5-mini-instruct costs less

For input processing, GPT OSS 120B ($0.09/1M tokens) is 1.1x cheaper than Phi-3.5-mini-instruct ($0.10/1M tokens).

For output processing, GPT OSS 120B ($0.45/1M tokens) is 4.5x more expensive than Phi-3.5-mini-instruct ($0.10/1M tokens).

In conclusion, GPT OSS 120B 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
Sun Sep 06 2026 • llm-stats.com
OpenAI
GPT OSS 120B
Input tokens$0.09
Output tokens$0.45
Best providerDeepinfra
Microsoft
Phi-3.5-mini-instruct
Input tokens$0.10
Output tokens$0.10
Best providerAzure
Notice missing or incorrect data?Start an Issue

Model Size

Parameter count comparison

113.0B diff

GPT OSS 120B has 113.0B more parameters than Phi-3.5-mini-instruct, making it 2973.7% larger.

OpenAI
GPT OSS 120B
116.8Bparameters
Microsoft
Phi-3.5-mini-instruct
3.8Bparameters
116.8B
GPT OSS 120B
3.8B
Phi-3.5-mini-instruct

Context Window

Maximum input and output token capacity

GPT OSS 120B accepts 131,072 input tokens compared to Phi-3.5-mini-instruct's 128,000 tokens. GPT OSS 120B can generate longer responses up to 131,072 tokens, while Phi-3.5-mini-instruct is limited to 128,000 tokens.

OpenAI
GPT OSS 120B
Input131,072 tokens
Output131,072 tokens
Microsoft
Phi-3.5-mini-instruct
Input128,000 tokens
Output128,000 tokens
Sun Sep 06 2026 • llm-stats.com

License

Usage and distribution terms

GPT OSS 120B is licensed under Apache 2.0, 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 OSS 120B

Apache 2.0

Open weights

Phi-3.5-mini-instruct

MIT

Open weights

Release Timeline

When each model was launched

GPT OSS 120B was released on 2025-08-05, while Phi-3.5-mini-instruct was released on 2024-08-23.

GPT OSS 120B is 12 months newer than Phi-3.5-mini-instruct.

GPT OSS 120B

Aug 5, 2025

1.1 years ago

11mo newer
Phi-3.5-mini-instruct

Aug 23, 2024

2.0 years ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

GPT OSS 120B is available from DeepInfra, Novita, OpenAI, Fireworks, Groq. Phi-3.5-mini-instruct is available from Azure.

GPT OSS 120B

deepinfra logo
Deepinfra
Input Price:Input: $0.09/1MOutput Price:Output: $0.45/1M
novita logo
Novita
Input Price:Input: $0.10/1MOutput Price:Output: $0.50/1M
openai logo
OpenAI
Input Price:Input: $0.10/1MOutput Price:Output: $0.50/1M
fireworks logo
Fireworks
Input Price:Input: $0.15/1MOutput Price:Output: $0.60/1M
groq logo
Groq
Input Price:Input: $0.15/1MOutput Price:Output: $0.60/1M

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

Judge for yourself.

Run your own prompts against GPT OSS 120B and Phi-3.5-mini-instruct side-by-side, then vote on the output you prefer.

GPT OSS 120B
✓ Preferred
Phi-3.5-mini-instruct
Open in Playground

FAQ

Common questions about GPT OSS 120B vs Phi-3.5-mini-instruct.

Which is better, GPT OSS 120B or Phi-3.5-mini-instruct?

GPT OSS 120B leads the LLM Stats Score 29.2 to -3.8. GPT OSS 120B is made by OpenAI and Phi-3.5-mini-instruct is made by Microsoft. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does GPT OSS 120B compare to Phi-3.5-mini-instruct in benchmarks?

GPT OSS 120B scores MMLU: 90.0%, CodeForces: 82.1%, GPQA: 80.1%, TAU-bench Retail: 67.8%, HealthBench: 57.6%. Phi-3.5-mini-instruct scores GSM8k: 86.2%, ARC-C: 84.6%, RULER: 84.1%, PIQA: 81.0%, OpenBookQA: 79.2%.

Is GPT OSS 120B cheaper than Phi-3.5-mini-instruct?

GPT OSS 120B is 1.1x cheaper for input tokens. GPT OSS 120B costs $0.09/M input and $0.45/M output via deepinfra. 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 OSS 120B and Phi-3.5-mini-instruct?

GPT OSS 120B supports 131K 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 OSS 120B and Phi-3.5-mini-instruct?

Key differences include LLM Stats Score (29.2 vs -3.8), context window (131K vs 128K), input pricing ($0.09 vs $0.10/M), licensing (Apache 2.0 vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT OSS 120B and Phi-3.5-mini-instruct?

GPT OSS 120B is developed by OpenAI and Phi-3.5-mini-instruct is developed by Microsoft.