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GPT-6 Astra vs Phi-3.5-mini-instruct

GPT-6 Astra leads the LLM Stats Score 60.7 to -3.8. Phi-3.5-mini-instruct is 200.0x cheaper per token.

OpenAI · Microsoft · Updated for 2026

Which is better?

GPT-6 Astra leads the overall LLM Stats Score 60.7 to -3.8, ranking #1 overall.

In the 1 individual benchmarks reported for both models, GPT-6 Astra wins 1; this is a narrower head-to-head signal than the composite indexes.

On price, Phi-3.5-mini-instruct is roughly 200.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-6 Astra also accepts a larger context window (1,050,000 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 GPT-6 Astra

  • overall performance matters — it scores 60.7 and ranks #1 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results
  • you process long inputs — it offers a 1,050,000 token context window
  • you want the most recent training data — it shipped Sep 2026

Choose Phi-3.5-mini-instruct

  • cost matters — it's about 200.0x cheaper per token
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Core performance indexes
60.7
#1
-3.8
#334
58.7
#1
-4.7
#331
49.0
#1
-6.8
#253
Cost, coverage & limits
Benchmark wins
1 of 1
0 of 1
Input price
$10.00 / M
$0.10 / M
Output price
$50.00 / M
$0.10 / M
Context window
1,050,000
128,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
GPT-6 Astra
Phi-3.5-mini-instruct
35.3#42
-1.1#295
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

22 reported for GPT-6 Astra · 31 for Phi-3.5-mini-instruct

1 shared

GPT-6 Astra outperforms in 1 benchmarks (GPQA), while Phi-3.5-mini-instruct is better at 0 benchmarks.

GPT-6 Astra significantly outperforms across most benchmarks.

Fri Sep 04 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-6 Astra ($10.00/1M tokens) is 100.0x more expensive than Phi-3.5-mini-instruct ($0.10/1M tokens).

For output processing, GPT-6 Astra ($50.00/1M tokens) is 500.0x more expensive than Phi-3.5-mini-instruct ($0.10/1M tokens).

In conclusion, GPT-6 Astra 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
Fri Sep 04 2026 • llm-stats.com
OpenAI
GPT-6 Astra
Input tokens$10.00
Output tokens$50.00
Best providerOpenAI
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

GPT-6 Astra accepts 1,050,000 input tokens compared to Phi-3.5-mini-instruct's 128,000 tokens. Both models can generate responses up to 128,000 tokens.

OpenAI
GPT-6 Astra
Input1,050,000 tokens
Output128,000 tokens
Microsoft
Phi-3.5-mini-instruct
Input128,000 tokens
Output128,000 tokens
Fri Sep 04 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

GPT-6 Astra supports multimodal inputs, whereas Phi-3.5-mini-instruct does not.

GPT-6 Astra can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT-6 Astra

Text
Images
Audio
Video

Phi-3.5-mini-instruct

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-6 Astra 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-6 Astra

Proprietary

Closed source

Phi-3.5-mini-instruct

MIT

Open weights

Release Timeline

When each model was launched

GPT-6 Astra was released on 2026-09-03, while Phi-3.5-mini-instruct was released on 2024-08-23.

GPT-6 Astra is 25 months newer than Phi-3.5-mini-instruct.

GPT-6 Astra

Sep 3, 2026

0 days ago

2.0yr newer
Phi-3.5-mini-instruct

Aug 23, 2024

2.0 years ago

Knowledge Cutoff

When training data ends

GPT-6 Astra has a documented knowledge cutoff of 2026-04-30, while Phi-3.5-mini-instruct's cutoff date is not specified.

We can confirm GPT-6 Astra's training data extends to 2026-04-30, but cannot make a direct comparison without Phi-3.5-mini-instruct's cutoff date.

GPT-6 Astra

Apr 2026

Phi-3.5-mini-instruct

Provider Availability

GPT-6 Astra is available from OpenAI. Phi-3.5-mini-instruct is available from Azure.

GPT-6 Astra

openai logo
OpenAI
Input Price:Input: $10.00/1MOutput Price:Output: $50.00/1M

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-6 Astra and Phi-3.5-mini-instruct side-by-side, then vote on the output you prefer.

GPT-6 Astra
✓ Preferred
Phi-3.5-mini-instruct
Open in Playground

FAQ

Common questions about GPT-6 Astra vs Phi-3.5-mini-instruct.

Which is better, GPT-6 Astra or Phi-3.5-mini-instruct?

GPT-6 Astra leads the LLM Stats Score 60.7 to -3.8. GPT-6 Astra 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-6 Astra compare to Phi-3.5-mini-instruct in benchmarks?

GPT-6 Astra scores ExploitBench: 100.0%, ARC-AGI-3: 99.9%, ARC-AGI: 98.5%, FrontierMath Tier 4 (v2): 97.6%, GPQA: 96.0%. Phi-3.5-mini-instruct scores GSM8k: 86.2%, ARC-C: 84.6%, RULER: 84.1%, PIQA: 81.0%, OpenBookQA: 79.2%.

Is GPT-6 Astra cheaper than Phi-3.5-mini-instruct?

Phi-3.5-mini-instruct is 100.0x cheaper for input tokens. GPT-6 Astra costs $10.00/M input and $50.00/M output via openai. 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-6 Astra and Phi-3.5-mini-instruct?

GPT-6 Astra supports 1.1M 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-6 Astra and Phi-3.5-mini-instruct?

Key differences include LLM Stats Score (60.7 vs -3.8), context window (1.1M vs 128K), input pricing ($10.00 vs $0.10/M), multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-6 Astra and Phi-3.5-mini-instruct?

GPT-6 Astra is developed by OpenAI and Phi-3.5-mini-instruct is developed by Microsoft.