The AI arena is free today

Open Superagent

Claude Opus 5.5 vs Mistral Medium 3.5

Claude Opus 5.5 leads the LLM Stats Score 60.3 to 26.9. Mistral Medium 3.5 is 2.7x cheaper per token.

Anthropic · Mistral AI · Updated for 2026

Which is better?

Claude Opus 5.5 leads the overall LLM Stats Score 60.3 to 26.9, ranking #1 overall.

On price, Mistral Medium 3.5 is roughly 2.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Claude Opus 5.5 also accepts a larger context window (1,000,000 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 Claude Opus 5.5

  • overall performance matters — it scores 60.3 and ranks #1 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you process long inputs — it offers a 1,000,000 token context window
  • you want the most recent training data — it shipped Sep 2026

Choose Mistral Medium 3.5

  • cost matters — it's about 2.7x cheaper per token
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Claude Opus 5.5
Anthropic
Mistral Medium 3.5
Mistral AI
Core performance indexes
LLM Stats Score
60.3
#1
26.9
#153
Reasoning
58.4
#1
27.2
#145
Coding
51.4
#1
23.7
#82
Agents
45.7
#2
8.9
#138
Cost, coverage & limits
Benchmark wins
—
—
Input price
$4.00 / M
$1.50 / M
Output price
$20.00 / M
$7.50 / M
Context window
1,000,000
256,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Opus 5.5
Mistral Medium 3.5
Math
42.7#4
18.9#174
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

31 reported for Claude Opus 5.5 · 11 for Mistral Medium 3.5

No common benchmarks found

Claude Opus 5.5 and Mistral Medium 3.5don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

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, Claude Opus 5.5 ($4.00/1M tokens) is 2.7x more expensive than Mistral Medium 3.5 ($1.50/1M tokens).

For output processing, Claude Opus 5.5 ($20.00/1M tokens) is 2.7x more expensive than Mistral Medium 3.5 ($7.50/1M tokens).

In conclusion, Claude Opus 5.5 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 Oct 02 2026 • llm-stats.com
Anthropic
Claude Opus 5.5
Input tokens$4.00
Output tokens$20.00
Best providerAnthropic
Mistral AI
Mistral Medium 3.5
Input tokens$1.50
Output tokens$7.50
Best providerMistral
Notice missing or incorrect data?

Context Window

Maximum input and output token capacity

Claude Opus 5.5 accepts 1,000,000 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 Claude Opus 5.5 is limited to 128,000 tokens.

Anthropic
Claude Opus 5.5
Input1,000,000 tokens
Output128,000 tokens
Mistral AI
Mistral Medium 3.5
Input256,000 tokens
Output256,000 tokens
Fri Oct 02 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Opus 5.5 and Mistral Medium 3.5 support multimodal inputs.

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

Claude Opus 5.5

Text
Images
Audio
Video

Mistral Medium 3.5

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Opus 5.5 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.

Claude Opus 5.5

Proprietary

Closed source

Mistral Medium 3.5

Modified MIT License

Open weights

Release Timeline

When each model was launched

Claude Opus 5.5 was released on 2026-09-22, while Mistral Medium 3.5 was released on 2026-04-29.

Claude Opus 5.5 is 5 months newer than Mistral Medium 3.5.

Claude Opus 5.5

Sep 22, 2026

1 weeks ago

4mo newer
Mistral Medium 3.5

Apr 29, 2026

5 months ago

Knowledge Cutoff

When training data ends

Claude Opus 5.5 has a documented knowledge cutoff of 2026-06-01, while Mistral Medium 3.5's cutoff date is not specified.

We can confirm Claude Opus 5.5's training data extends to 2026-06-01, but cannot make a direct comparison without Mistral Medium 3.5's cutoff date.

Claude Opus 5.5

Jun 2026

Mistral Medium 3.5

—

Provider Availability

Claude Opus 5.5 is available from Anthropic. Mistral Medium 3.5 is available from Mistral AI.

Claude Opus 5.5

anthropic logo
Anthropic
Input Price:Input: $4.00/1MOutput Price:Output: $20.00/1M

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?

Judge for yourself.

Run your own prompts against Claude Opus 5.5 and Mistral Medium 3.5 side-by-side, then vote on the output you prefer.

Claude Opus 5.5
✓ Preferred
Mistral Medium 3.5
Open in Playground

FAQ

Common questions about Claude Opus 5.5 vs Mistral Medium 3.5.

Which is better, Claude Opus 5.5 or Mistral Medium 3.5?

Claude Opus 5.5 leads the LLM Stats Score 60.3 to 26.9. Claude Opus 5.5 is made by Anthropic 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 Claude Opus 5.5 compare to Mistral Medium 3.5 in benchmarks?

Claude Opus 5.5 scores BenchCAD (with Python tool): 96.2%, Global-MMLU: 94.3%, SWE-bench Multilingual: 93.9%, MILU: 93.1%, ArXivMath: 91.2%. 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 Claude Opus 5.5 cheaper than Mistral Medium 3.5?

Mistral Medium 3.5 is 2.7x cheaper for input tokens. Claude Opus 5.5 costs $4.00/M input and $20.00/M output via anthropic. Mistral Medium 3.5 costs $1.50/M input and $7.50/M output via mistral.

What are the context window sizes for Claude Opus 5.5 and Mistral Medium 3.5?

Claude Opus 5.5 supports 1.0M 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 Claude Opus 5.5 and Mistral Medium 3.5?

Key differences include LLM Stats Score (60.3 vs 26.9), context window (1.0M vs 256K), input pricing ($4.00 vs $1.50/M), licensing (Proprietary vs Modified MIT License). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5.5 and Mistral Medium 3.5?

Claude Opus 5.5 is developed by Anthropic and Mistral Medium 3.5 is developed by Mistral AI.

Related comparisons