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GPT-6 Astra vs Mistral Medium 3.5

GPT-6 Astra leads the LLM Stats Score 59.9 to 26.9. Mistral Medium 3.5 is 6.7x cheaper per token.

OpenAI · Mistral AI · Updated for 2026

Which is better?

GPT-6 Astra leads the overall LLM Stats Score 59.9 to 26.9, 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, Mistral Medium 3.5 is roughly 6.7x 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 59.9 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 Mistral Medium 3.5

  • cost matters — it's about 6.7x 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
59.9
#1
26.9
#144
57.9
#1
27.3
#136
48.5
#1
23.7
#74
46.4
#1
9.2
#128
Cost, coverage & limits
Benchmark wins
1 of 1
0 of 1
Input price
$10.00 / M
$1.50 / M
Output price
$50.00 / M
$7.50 / M
Context window
1,050,000
256,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
GPT-6 Astra
Mistral Medium 3.5
36.0#42
18.9#171
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

22 reported for GPT-6 Astra · 11 for Mistral Medium 3.5

1 shared

GPT-6 Astra outperforms in 1 benchmarks (BrowseComp), while Mistral Medium 3.5 is better at 0 benchmarks.

GPT-6 Astra significantly outperforms across most benchmarks.

Fri Sep 11 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Mistral Medium 3.5 costs less

For input processing, GPT-6 Astra ($10.00/1M tokens) is 6.7x more expensive than Mistral Medium 3.5 ($1.50/1M tokens).

For output processing, GPT-6 Astra ($50.00/1M tokens) is 6.7x more expensive than Mistral Medium 3.5 ($7.50/1M tokens).

In conclusion, GPT-6 Astra is more expensive than Mistral Medium 3.5.*

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

Lowest available price from all providers
Fri Sep 11 2026 • llm-stats.com
OpenAI
GPT-6 Astra
Input tokens$10.00
Output tokens$50.00
Best providerOpenAI
Mistral AI
Mistral Medium 3.5
Input tokens$1.50
Output tokens$7.50
Best providerMistral
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 Mistral Medium 3.5's 256,000 tokens. Mistral Medium 3.5 can generate longer responses up to 256,000 tokens, while GPT-6 Astra is limited to 128,000 tokens.

OpenAI
GPT-6 Astra
Input1,050,000 tokens
Output128,000 tokens
Mistral AI
Mistral Medium 3.5
Input256,000 tokens
Output256,000 tokens
Fri Sep 11 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both GPT-6 Astra and Mistral Medium 3.5 support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

GPT-6 Astra

Text
Images
Audio
Video

Mistral Medium 3.5

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-6 Astra is licensed under a proprietary license, while Mistral Medium 3.5 uses Modified MIT License.

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

GPT-6 Astra

Proprietary

Closed source

Mistral Medium 3.5

Modified MIT License

Open weights

Release Timeline

When each model was launched

GPT-6 Astra was released on 2026-09-04, while Mistral Medium 3.5 was released on 2026-04-29.

GPT-6 Astra is 4 months newer than Mistral Medium 3.5.

GPT-6 Astra

Sep 4, 2026

6 days ago

4mo newer
Mistral Medium 3.5

Apr 29, 2026

4 months ago

Knowledge Cutoff

When training data ends

GPT-6 Astra has a documented knowledge cutoff of 2026-04-30, while Mistral Medium 3.5'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 Mistral Medium 3.5's cutoff date.

GPT-6 Astra

Apr 2026

Mistral Medium 3.5

Provider Availability

GPT-6 Astra is available from OpenAI. Mistral Medium 3.5 is available from Mistral AI.

GPT-6 Astra

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

Mistral Medium 3.5

mistral logo
Mistral
Input Price:Input: $1.50/1MOutput Price:Output: $7.50/1M
* 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 Mistral Medium 3.5 side-by-side, then vote on the output you prefer.

GPT-6 Astra
✓ Preferred
Mistral Medium 3.5
Open in Playground

FAQ

Common questions about GPT-6 Astra vs Mistral Medium 3.5.

Which is better, GPT-6 Astra or Mistral Medium 3.5?

GPT-6 Astra leads the LLM Stats Score 59.9 to 26.9. GPT-6 Astra is made by OpenAI and Mistral Medium 3.5 is made by Mistral AI. 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 Mistral Medium 3.5 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%. Mistral Medium 3.5 scores COLLIE: 95.8%, Tau3 Telecom: 91.4%, AIME 2025: 86.3%, SWE-Bench Verified: 77.6%, Tau3 Retail: 76.1%.

Is GPT-6 Astra cheaper than Mistral Medium 3.5?

Mistral Medium 3.5 is 6.7x cheaper for input tokens. GPT-6 Astra costs $10.00/M input and $50.00/M output via openai. Mistral Medium 3.5 costs $1.50/M input and $7.50/M output via mistral.

What are the context window sizes for GPT-6 Astra and Mistral Medium 3.5?

GPT-6 Astra supports 1.1M tokens and Mistral Medium 3.5 supports 256K 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 Mistral Medium 3.5?

Key differences include LLM Stats Score (59.9 vs 26.9), context window (1.1M vs 256K), input pricing ($10.00 vs $1.50/M), licensing (Proprietary vs Modified MIT License). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-6 Astra and Mistral Medium 3.5?

GPT-6 Astra is developed by OpenAI and Mistral Medium 3.5 is developed by Mistral AI.